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Human Factors Research Needs for an Aging Population (1990)

Chapter: 2. Human Factors Problems Associated with Aging

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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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Suggested Citation:"2. Human Factors Problems Associated with Aging." National Research Council. 1990. Human Factors Research Needs for an Aging Population. Washington, DC: The National Academies Press. doi: 10.17226/1518.
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2 Human Factors Problems Associated With Aging When identifying human factors problems relevant to aging, an initiad step rs to define and characterize the subpopulation of interest. Typically, the "agent are defined as all persons 65 years old and over, with further Extinctions made between the ~young- old~ (65-74 yeam old) and the "old-old~ (85 years old and over). However, this characterization of the older population is grossly oversimplified. Aging is continuous and it does not start suddenly at age 65. Moreover, the changes in physiological and psychological functioning that often accompany aging are by no means uniform in their onset, aIld the social, psychological, and physical changes associated with advancing age are unevenly distributed among the elderly. Therefore, using chronological age to characterize or predict an older person's behavioral and functional capacities Is likely to prove inadequate. Many gerontology researchers have suggested that new methods are needed that more accurately describe a person's condition, capabilities, and maturational trajectory. We support the objectives of separating the functional characteristics of interest from the uncertain statistical predictor variable of age and of avoiding the stigma of age labels. On the other hand, we would not favor the development and use of any single omnibus measure of "functional age" as has sometimes been suggested. Essentially, such a measure would be derived by identifying variables related to age, measuring performance levels for these variables, and combining the measures into a composite index using some form of multivariate analysis. This type of measure 7

8 HUMAN FACTORS RESEARCH NEEDS FOR AN AGING POPULATION would have many of the faults that chronological age has as a mea- sure, hiding the large amounts of variability and lack of correlation among different manifestations of age-related changes. By contrasts a functional assessment battery that retained the distinctions between different abilities would be valuable. Of special interest would be research to discoverer predictive relationships between deficits in one function and another as a guide to possible prophylactic strategies. For the purpose of formulating research, development, and policy goals, the significant fact is that many changes in capabilities are closely related to aging by links involving biological factors, social customs, or the benefits and deficits inherent in longevity. These changes alter performance and, in quantitative and qualitative ways, the nature of an "optimally environment. However, we strongly urge that the large variability among older individuals be kept in clear focus. We do not want to produce behavioral or design prescriptions for the "house of ~ 70 year old." Rather, we would like to say, for example, that, for a given age distribution ~ a population, bathtubs of a particular design would be beneficial. It would be better still to specify a design that will serve everyone well irrespective of age (Fozard, 1981~. The subsequent sections of this report will consider some data on the characteristics and needs of our aging population. ,, _ ~ , DEMOGRAPHICS, ECOLOGY, AND SOClO[OGY In order to provide a more complete picture of the subpopu- lation of interest, this section presents information regarding the living patterns of older adults. The tables presented here describe salient demographic characteristics of the older adult population of the United States. These characteristics include information regard- ing the projected age structure of the older population through the year 2050, the living arrangements of older adults, and their work and retirement patterns. Table 1 shows the age distribution of older people in the United States as projected through the year 2050 (Myers, 1985~. As shown in the table, the number of older people living in the United States will continue to increase over the next several decades. Until the year 2000, the number of older persons is expected to increase across all age categories, but the gain will be particularly large for persons aged 80 years old and over. Generally, there is a progressive sex imbalance in the older population, with an increasing proportion of females at

H~4N FACTORS PROBLEMS ASSOC7lATE:W WIT7I AGING TABLE 1 Projected Numbers of People 65+ Years in the United States (in thousande) Year Population Group 1980 2000 2025 2050 Number/aged population 25,708 35,036 58,636 67,060 Percent/total population 11.3 lS.1 19.5 21.1 Ages--number 65-69 8,805 9,110 18,314 16,591 70-74 6,843 8,583 13,774 13,431 75-79 4,815 7,242 11,103 11,352 80-84 2,972 4,965 6,767 9,624 85+ 2,274 5,136 7,678 16,063 Ages-percent 100.0 100.0 100.0 100.0 65-69 34.2 26.0 31.2 24.7 70-74 26.6 24.S 25.2 20.0 75-79 18.7 20.7 18.9 16.9 80-84 11.6 14.2 11.5 14.4 85+ 8.8 14.6 13.1 24.0 Source: Adapted from Myers (1985:Table 43. 9 older ages. The sex ratio for people aged 65-70 in the year 2050 is estimated at three males for every four females. Among people 80 years old and over, there will be two femades for every male (Myers, 1985). In addition, the aged population itself is growing older. In 1900 the average life expectancy of people aged 65 was an additional 11.9 years, ~ compared with an additional 17.0 years in 1983. By the year 2000 those aged 75~4 wiD constitute about one-third of elderly persons and those 85 and over win represent about 15 percent (Office Of Technology Assessment, 1985~. This means that there win be a greater number of very old persons living ~ the United States. The growth in the number of people in the oldest age brackets has signif- icant implication for human factors engineering because people in older age groups typically have greater problems maintaining func- tional independence and warrant more environmental and service support. Table 2 presents data regarding the living arrangements of older people. It shows that most older adults live in a household either

10 HUMAN FACTOR ARCH NEWS FOR AN AGING POPULATION TABLE 2 Living Arrangements of the Population Aged 65 and Over, by Age and Sex; United States, 1970 and 1981 (percent distribution) Year and Male Ages Living Arrangement 65+ 65-74 75+ Female Ages 65+ 65-74 75+ 1970: In households 95.5% 96.4% 93.796 95.0% 97.6% 91.156 Living alone 14.1 11.3 19.1 33.8 31.6 37.0 Spouse present 69.9 75.2 60.4 33.9 43.5 19.1 With someone else 11.5 9.9 14.2 27.4 22.4 35.0 Not in households 4.5 3.6 6.3 5.0 2.4 8.9 Total 100.0 100.() 100.0 100.0 100.0 100.0 1981: In households Living alone Spouse present With someone else Not in households Total 96.2 97.9 92.9 93.8 97.8 88.3 13.8 11.1 19.0 38.8 34.2 45.1 74.1 79.0 64.S 35.5 47.3 19.3 8.3 7.8 9.1 19.4 16.2 23.8 3.8 2.1 7.1 6.3 2.2 11.7 100.0 100.0 100.0 100.0 100.0 100.0 Source: Office of Technology Assessment (1985:Table 25~. alone or with a spouse. In the older age group (75~) the likelihood of living alone increases, especially for women. ~ fact, the proportion of elderly women living alone has markedly increased since 1970. In general, the number of older people living in nursing homes has increased since 1960. In 1983, 5 percent of persons age 65 years old and older lived In nursing homes as compared with approximately 3 percent in 1960. However, this increase is largely due to the increased number of the old-old cohort. It is anticipated that by the year 2020 there will be 3 million elderly persons in nursing homes, more than half of whom will be age 85 and over. Also, the proportion of institutionalized elderly has decreased for the young- old and increased mnong the old-old. These trends are expected to persist through the next decade. However, the most dramatic trend projected is the increased number of females living alone. With respect to housing, the majority of older adults own their own homes. In 1980, among the 16.5 million elderly households, about 12.3 million were owner occupied and only 4.2 million were renter occupied. It is expected that the number of elderly owned

BUJ~IN FACTORS PROBLEMS ASSOCL4TED WITH AGING 11 households will continue to increase (Office of Technology Assess meet, 1985~. This is due to the growth in the elderly population and to the fact that older people are less likely to move than younger people. The growth ~ households maintained by older persons un- derscores the need to attend to the housing problems of the elderly. These problems arise from the fact that older people tend to live in housing that ~ older than that occupied by younger people (Lawson, 19853. As ~ result, housing deficiencies, such as broken stairs or poor electrical wiring, are more common in elderly households. While the disrepair found in the homes of many older people is attributable to the fact that they live in older homes, the problem persists because their incomes are often not sufficient to cover the cost of repairs. This is not surprising in view of the fact that approximately 15 percent of the elderly live below the poverty line, a figure that doubles among older women living alone (Office of Technology Assessment, 1985~. Data also medicate that there is an increasing trend among older people to live ~ the suburbs of major cities. Because suburban areas tend to have less accessible public transportation and older people generally find driving progressively difficult, it may be that greater attention should be paid to the mobility problems commonly experienced by the elderly in order to enhance their functional inde- pendence. Regarding employment status, as shown In Table 3, the labor force participation rates of older adults are declining. Since 1950 the proportion of older men In the work force has declined. In 1950 men aged 65 years old and over represented 45 percent of the work force as compared with 18 percent in 1982. A similar pattern is observed for men aged 55 64 (BeD and MarcIsy, 1987~. Factors that may have contributed to this decline include increased availability of early retirement options, changes In health or attitudes about health and work, forced retirements, age discrimination, psycholog- ical "burnout, skill obsolescence, and increased desire for leisure. Howe crer, hypotheses about the changing male work patterns have not yet been substantiated. The labor force participation rate for women over 65 has declined only slightly, from 6 percent in 1950 to 5 percent in 1984. However, for women aged 55 64, participation in the work force has increased to around 41 percent (Robinson, Coberly, and Paul, 1985~. The types of jobs held by older adults are shown in Table 4. Most older people, especially women, tend to be concentrated in the

12 HUMAN FACTORS RESEARCH NEEDS FOR AN AGING POPULATION TABLE 3 Labor Force Participation Rates by Age and Sex Through 1995 (percent) Population Actual Group 1981 Estimated Projected 1985 1990 1995 Total 106,393 (thousands) Men 114,985 122,375 127,542 16-24 12.2 10.9 9.2 8.3 25-54 36.4 36.5 37.7 38.2 55-64 6.7 6.2 5.4 5.1 65+ 1.7 1.6 1.S 1.3 55+ 8.4 7.8 6.9 6.4 Women 16-24 10.7 10.3 9.2 8.8 25-54 26.8 29.3 32.2 33.7 55-64 4.4 4.1 3.6 3.5 65+ 1.1 1.0 1.0 1.0 55+ 5.5 5.1 4.6 4.5 Both sexes 16-24 22.9 21.3 18.5 17.1 25-54 63.2 65.8 70.0 72.0 55-64 11.0 10.S 9.1 8.6 65+ 2.8 2.6 2.5 2.3 55+ 13.8 12.9 11.6 10.9 Source: Adapted from Robinson, Coberly, and Paul (1985:T~ble 1~. service sector. Eighteen percent of employed men over 65 are in man- agement, 15 percent are engaged in professional technical work, and 13 percent are in service occupations. The pattern for female workers is different. Employed women, aged 45 64 (40 percent) and 65 years old and over (25 percent) tend to be ~ clerical occupations (Office of Technology Assessment, 1985~. This suggests that large num- bers of older workers wiD be affected by developments in computers, communications, and other expanding office technologies. Overall, it ~ clear Tom the data that work and living situations vary considerably as a function of age and that the shifting distribu- tion of the population will consequently create major changes in the distribution of life-styles among the old. The important questions for our purposes, however, are how these changes are reflected in the everyday adaptive demands on individuab; the ways in which individuals are, or are not, able to meet these demands; and the

HUAf4NFACTORSPROBLEI~SASSOCIATEIDWITHAGING TABLE 4 Industry Distribution of Employed Men and Women Aged 45+, 1980 (percent) Men Women Industry 45-54 55-59 60-64 65+ 45-54 55-59 60-64 65 Mining 1 1 1 1 0.3 0.2 -- -- Construction 10 9 8 6 1 ~ 1 -- Manufacturing 29 29 28 12 19 18 17 9 Durable 20 19 18 7 9 9 8 3 Nondurable 9 10 10 5 10 9 9 6 Transportation 10 10 8 4 3 3 3 1 Trade 15 15 16 21 20 19 21 26 Wholesale 5 5 5 5 2 2 2 2 Retail 10 10 11 16 18 17 19 24 Financing/~nsurance real estate 5 5 5 7 8 ~ 6 6 Services 18 18 20 30 40 40 41 42 Public administration 8 7 6 5 5 6 4 3 Agriculture 4 5 ~ 14 1 1 2 2 Private household ~ 3 4 5 11 Source: Office of Technology Assessment (1985:Table E-1~. 13 requirements and opportunities for improvements based on human factors research. A good deal is known about the incidence of vari- ous diseases and medical disabilities and a certain a~nount about the "normals changes in functional abilities that come with age; we wiD present examples of such data shortly. But we also need to know about the distribution of demands for various capabilities, and here is where the data are weakest. Ne~rerthele=, some useful evidence is available. We will review some highlights of this knowledge in the categories of home activities, work activities, transportation and communication, safety and security, =d leisure. HOM1: ACTIVITIES Examination of the home activities of older people is a good starting point in our discussion in that (~) an increasing number of older people live atone at home; (2) older people spend the majority of their time at home, with a large portion of this time allocated to personal daily living activities; (3) older people frequently report difficulty completing home activities; and (4) there is some detailed -

14 HUMAN FACTORS RESEARCH NEEDS FOR AN AGING POP UNCTION knowledge available regarding the demands associated with home tasks and the problems older people have in meeting these demands. To some extent this knowledge can be generalized to other domains. Household behaviors are complex ~d involve a number of physio- logical and psychologicad subprocesses that are corn to factors in most task performance. In this context it is useful to d~t~gu~h between basic activi- ties of daily living (ADL) and instrumental activities of daily living (IADL), as this categorization is frequently used in the literature. Basic activities of daily living include bathing, dreming, toiletting, transferring, continence, and feeding. Instrumental activities, which reflect the capacity to adapt to one's environment, include such tasks as shopping, housework and yardwork, handling money, and driving (Katz, Ford, Moskowitz, Jackson, and Jaffee, 1963~. Table 5 presents summary data reflecting the amount of time older people spend perfortn~ng various household tasks. Because we do not have nationally representative data on how older people allocate their tone to different activities, these data are limited to a restricted range of activities and are based on a small s~nple of people. Studies of day-t>day patterns of time use have tended to omit the elderly or have focused on their leisure activities. Moss and Lawton (1982) collected tim~budget data from small selected samples `>f independent (n = 426) and nonindependent (n = 1643 elderly people. Their data give a more detailed picture of how older people allocate their time to various daily living activities (Table 63. The data also indicate that older people allocate ~ large portion of their tune to home tasks, to the extent that 82 percent of ~] waking- tune behaviors occur in the home. About one-third of the day is devoted to basic activities of daily living. Comparison of the time budgets of the independent and nonindepenclent samples indicate that the latter group's activities are heavily weighted toward personal care ~d away from instrumental activities. The major difference ill. discretionary behaviors between these groups ~ the higher level of "inacti~rity~ among the impaired (I,awton, 1987~. It is reasonable to ask whether the Ieve] of inactivity among the nonindependent elderly would be reduced if the task demands of certain instrumental activities were reduced. In general, data regarding activity frequency are useful in sug- gest~ng activities and activity groups that should be investigated. However, while such data represent a good starting point, they do not provide sufficient detail to target specific areas for human factors

HUMAN FACTOR PROBLEMS ASSOCIATE WITH AGING TABLE 5 Time Spent Performing Within-Home Activities Among a Sample of Elderly People Percentage Median Hours who Engaged Spent by All Behavior in Behavior Engaged Eating, cooking 99 2.5 Pemonai care 97 1.0 Television 70 3.0 Housework 67 2.0 Reading 61 1.0 Napping, idleness 56 2.O Radio, records 17 1.5 Handiwork 15 2.0 Entertaining 9 2.5 Writing 8 1.S Crafts, collection 1 2.0 Source: Beyer and Woods (1963) as cited in Lawton (19773. 15 research. The kind of information that can better help research ef- forts derives from knowing what types of home activities are difficult for older people to perform and what difficulties they encounter when performing them. It is essential to understand the environmental d sign issues that interact with these difficulties. It is reasonably well established that older people often have difficulty performing home tasks such as cooking and cleaning. Such difficulties may be reflected in the high rate of home accidents among people 65 and over, which account for approximately 43 percent of aD home fatalities. The most common causes of accidental injury for older people are (1) falls on stairways, floors, and bathtubs; (2) burns/scalds from cooking, hot water, and fires, and (3) poisoning from gases and vapors (Sterm, Barrett, and Alexander, 1985~. The reasons for the high frequency of such accidents are complex but likely include the fact that older people spend a majority of their time at home; age-related changes in functional abilities make it more diffiluit to complete home tasks; and the demands of the home environment are often substantive in that the homes of the elderly tend to be older than those of younger people, are more likely to be difficult to operate and maintain, and are more often in need of repair. The high rate of home accidents among the elderly pouts to the need for a detailed understanding of the etiology -of these accidents (Lawson and Brody, 1969~.

16 HUMAN FACTORS RESI£ARC!I NEEDS FOR AN AGING POPULATION TABLE 6 Mean Minutes Reported in Selected Activities in 24-Hour Day Activity Impaired Independent Community Residents Residents Obligatory Activities Personal and health care 53 71 Eating 77 77 Shopping 22 13 lIousework/home maintenance 68 38 Cooking 69 45 Helping others 10 7 Social agency 2 9 Discretionary Activities Family interaction 58 51 Social interaction (nonfamily) 54 59 Religious activity, excluding services 10 7 Reading 59 52 Radio 28 33 Television 205 210 Recreation and hobbies 44 32 Rest and relaxation 128 200 Gap (unaccounted time) 24 31 Sleeping 456 452 Environmental Context (waking houre) In home or yard 790 8S8 Mean age 75.2 79.0 Percentage female 54 77 Number 426 164 Source: Moss and Lawton (1982~. To date, the study of accidents in older populations h" been hugely epidern~olog~cal. A more refined and efficient approach to these problems would be possible with greater knowledge of the proximal causes of incidents and their relative frequencies. However, the effect of contributors to such accidents could be reduced with currently available methods. For example, housing can be designed to minimize the number of trips up and down stairs for people who spend most of their time indoors. In addition, the fictional requirements associated with home tasks need to be examined and compared with data on the capabilities of older adults In order to determine why they are difficult for the elderly. Many researchers

HUA~4N FACTORS PROBLE:MSASSOCIAT~D WITlIAGING 17 have suggested that an older person's inability to function ~ various settings can be linked to disparities between demands generated by the design and structure of the environment and the capacity of the older individual to meet those demands (e.g., Lawton, 1977~. A recent study (Czaja, Drury, Hammond, Brill, and I,ofti, 1987) identified consumer products and environments that are hazardous to people aged 55 and over and conducted a human factors analysis of the most hazardous products. This allowed the difficulties inherent in the human-product-enviromnent interface to be identified and also highlighted possible intervention strategies. For example, scalding accidents ~ bathrooms or showers occur when the person operates the wrong water control, operates a control in the wrong direction, or ~ unable to react quickly enough or with enough force when the water suddenly increases in temperature. These results permit identification of possible intervention strategies, such ~ changing the design of water controls to incorporate better labeling, lower force requirements, standard layouts, and automatically regulated water temperature. Unfortunately, detailed data of this type are limited. The only data available on competence leveb of the elderly with respect to home activities are restricted to ADL and lADL activities, which is understandable smce these activities are critical to functional inch pendence. Tm addition, the data that are available generally report only the frequency with which older people have problems perform- ing certain tasks, although there are limited data on the types of problems encountered. Regarding the first issue, the best data come from a national sample studied in the Health Interview Survey (Na- tional Center for Health Statistics, 1987~. In this survey questions were asked in dichotomous frames of reference: whether or not the respondent experiences difficulty ~ perfor~rung a task and whether the respondent receiver help with the task. Table 7 shows the preva- lence of ADL impairments as weD as similar rates for a group of skies thought to be especially relevant to work. The tasks that are most problematic for older adults are bathing, transferring, shopping, meal preparation, and housework (National Center for Health Statistics, 1987; Dawson, Hendershot, and Fulton, 1987~. The sample also re- ports difficulty walking, reaching, maintaining postures for extended periods, and carrying heavy objects. These results are consistent with those of Czaja, Clark, Weber, and Faletti (1988~. In their study self-report data from a small sample (n = 250) of independent elderly

18 BUMAN FACTORS RESEARCH NEEDS FOR AN AGING POP'UL4T7ON TABLE 7 Percentage of 65+ Population with Activity Lunitations Have Difficulty Receive Performing Help with Activity Activity Activity Self-Care Activities (a) Eating 1.8 1.1 Using toilet d.S 2.2 Dressing 6.2 4.S Transfemug 8.0 2.8 Getting outside 9.6 5.S Bathing 9.8 6.0 Walking 18.7 4.7 One or more activities 22.7 9.6 Some Management Activities (a) Using telephone 4.8 S.0 Managing money 5.1 d.8 Preparing meals 7.1 6.0 Doinglight housework 7.1 6.2 Shopping 11.1 10.5 Doing henry housework 23.8 19.3 One or more activities 26.9 22.2 Work-Related Activities (b) Walking up 10 steps Standing 2 hours Sitting 2 hours Stooping, crouching, kneeling Reaching up over head Reaching out to shake }lands Grasping with fingers Lifting or carrying 25 pounce Lifting or carrying 10 pounce 18.9 27.8 10.1 SS.9 13.6 1.9 9.1 28.0 9.2 . _ . Sources: (a) Olson, Hendershot, and Fulton (1987:Tables 1-7). (b) Ko~rar and LaCroix (1987:Table 1). persons indicate that meal preparation and clean up, grocery show ping, and homework are difficult for older adults. Their data also include the types of problems experienced with these tasks, such as reaching and bending for cooking items while prepping meals, and problems locating items ~ grocery stores. The data alto indicate that other problems older people may en- counter include performing tasks related to cooking, such as reading

HIJA£AN FACTORS PROBLEMS ASSOC2LATlED WIT7I AGING 19 labeb on food products and manipulating jars and cooking utensib. In addition, visual changes probably contribute to the difficulties older people have in reading labels on products, controls, appliances, and shelves In grocery stores. Furthermore, estimates from the Nat tional Health Interview Survey medicate that about 45 percent of the population aged 6~74 report that they have arthritis, while 50 percent of those 75 add older report this condition. The reduction in range of motion, dexterity, and mobility Tom such a condition plays a major role in the functional limitations of the elderly (Stoudt, 1987~. In addition to epidem~olog~cal data, the relationship between functional processes and the more extended sequence of ADL behav- iors needs to be investigated. More research ~ needed at a level of analysm that allows behavior to be broken down into component- person-environment transactions. ~ other words, human factors task analysis techniques need to be applied to the study of household behaviors. Faletti (1984) succe~fuDy modified and applied task-analytic techniques to study meal preparation. By subjecting videotaped sequencer of older women engaged in cooking a mead to multiply judge coding, Fadetti evolved characterizations of the person-objec~ environment transactions, using the grammatical analogy of verb = action, object = environment, and subject = person. He found that simple repositioning of items is the most frequent meal preparation task. Repositioning tasks are associated with lift, carry, and lower motions and usually involve one hand perforTrung precision grips followed by power grips. A person most often performs these t~ks while standing at ~ kitchen counter, which has an average height of 36 inches. Understanding task demands in this level of detail provides insight into the types of problems older people may have with task completion. In this case, repositioning food items, groceries, and pots and pans may be difficult for elderly persons because of loss of hand grip strength. A recent study (Kosher and LaCroix, 1987) of independent elderly women aged 65-74 reported that over 35 percent have difficulty life mg or carrying 25 pounds, while an other 10 percent are completely unable to lift or carry that weight. Even at 10 pounds, lifting or carrying ~ difficult for over 10 percent and impossible for about 4 percent of the study population. Given these limitations, grocery shopping and certain housekeeping chores could be difficult for such women. Based on available data, it is logical to assume that task anal- ysis.methodology could lead to paliative interventions with respect

20 He FACTORS ARCH NEWS FOR AN AGING POP UNWON

lIU1~4N FACTORS PROBLEMS ASSOCIATED WITH AGING 21 Dixon (1984) have caned this process Unselective optimization with compensation. According to Lawton (1982, 1987), the process of change over tune in the way guns are enhanced at m~nnnum cost in lost task per- formance has never been studied. The mode} of Faletti's research can be applied in cros+sectional, and ultimately longitudinal, fashion to highlight how people's operation of utensils, fixed environmental fea- tures, and visual displays changes with sensory, motor, and perhaps cognitive decline. Current method of ADL performance amendment do not permit differentiation among those elderly who are still in- dependent, have altered their task behavior, given up some tasks in order to mental competence ~ others, or substituted prostheses for inefficient body structures. A careful study of such changes as they occur ~ anportant, as it would provide msight into the coping mechanisms of older adults (Lawson, 1987~. A final area to consider is housing design and the design ~d dissemination of additive devices. A constant theme within the gerontological literature ~ the strong desire of older people to remain in their own homes, despite persona unpa~rments and sometimes extensive decline in environmental quality. The results of the 1981 Annual Housing Surrey (Office of Policy Development and Research, 1983) indicate that approximately 13 percent of older people who live at home alone exhibit at least one major deficit in physical mobility. Other estimates suggest that of the 26 million older persons living in the community in 1983, 2.3 million needed some type of assistance to perform one or more basic IDLE and 2.7 million needed come type of Instance to perform in- strumental acti~ritie~ (Office of Technology Assessment, 1985~. Thm population constitutes a high-priority group for con~nunity-based in-home services, since these people are at high risk for institution- alization. There has been tremendous growth in the number of m-home services, such as home health visits and delivered meals, and in the development of assertive technologies that can extend the ability of the elderly to live independently. However, before the benefits of these technologies are fully realized, severed objectives must be accomplished. One is the development of an effective means to dis- serninate information regarding the availability of such technologies to older adults. Another is the development of methods to match services ~d technologies tenth m~i~ridu~s. A valid functional assess- ment protocol is important to achieving the latter goal. In addition,

22 HUMAN FACTORS RES1EARCN NEIEDS FOR AN AGING POPULAI7ON efforts must be directed toward designing products and devices that are accepted by the user population. Many times costive technology gies are rejected became they are cumbersome, Ugly, or difficult to use. Clearly, this ~ an area where hum" factors researcbers can make contributions. And, ~ a more genera sense, it remains unclear to what extent the applications of technology to the physical envi- ronments or te~hnologic~ aide within the home mitigate the need for supportive assistance. Finally, much needs to be done with respect to the physical d~ sign of the home env~ronrnent. The nature of housing occupied by most older persom ~ such that the kind of supportive environment they need to carrier out routine activities independently is not pros vided (Chapanis, 1974; Wise, Anderson, and Jones, 1979; Office of Technology Assessment, 1985~. Although some design guidelines for housing exist (e.g., Parsons, 1981), there are serious discrepancies in the available guidelines. This ~ due partly to the limited anthropo- metric and function e] data amiable on older people but also to the lack of detailed information of the kinds outlined above. Consider just these mthropometric issues. The aged as a group differ from younger people in body Size and shape, in range of body motion at the joints, and ~ overall body mobility and agility. Stature, eye height, sitting height, and limb lengths all show declines with age (Borkin, Cults, and Glynn, 1983~. These facts have practical signif- icance with respect to housing design. As noted by Stoudt (1965, 1987), the stature of 5th-percentile elderly women falls below the stature of Ist-percentile women ~ the general population. In most instances, the 5th percentile has been arbitrarily selected as the lower limit for design; thus, a large portion (about 35 percent under normal distribution assumptions) of older women are not accommodated by designing to this criterion. Systematic data on the functional anthro- pometry of older people and related issues of environmental design are important areas of research for human factors experts. ~ summary, withm the domain of home activities, the follow- ing types of knowledge are needed: (~) representative data on the frequency of home activities among older people, (2) detailed knowI- edge regarding rlifliculties older people have in performing home tasks, (3) knowledge regarding the appropriateness and effectiveness of Various assistive technologies, (4) methodologies for assessing the ability of older people to live independently ~ the community and for determining the level and type of support services needed, (5) representative anthropometric data on older populations, (6) design

H~J FACTORS PROBLEMS ASSOCLATI3D WITH AGING 23 guidelines for home env~rournents, and (7) design guidelines for the development of new additive devices. WOW ACTIVITIES The number of people who are gainfully employed decreases beyond age 55. Despite charges ~ laws regarding compulsory retire- ment age, the proportion of people in the older age groups who are employed kiss been decreasing and there has been an increase in early retirement. ~ 1980, 56 percent of all male and 69 percent of female social security beneficiaries were receiving reduced benefits due to early retirement. By 1995 workers age 55 and older will probably represent only 11 percent of the labor force compared with nearly 14 percent ~ 1981. The incidence of part-tune work also increases with age. In 1981 nearly half of workers aged 65 and older worked part tune. The incidence of part-tune work is slightly higher for females than males. Several surveys of older people have reported a prefer- ence for part time work, especially among those who are employed full tune but wish to remain employed after retirement. However, while some older people choose part-time work voluntarily, others are forced to reduce their work hours because of iline - , financial com- plications, layoffs, or limited opportunities for full-time employment (Robinson et at., 1985; Ko~rar and Lacrosse, 1987~. Overdo, the most significant change ~ the employment patterns of older people is their declining representation in the labor force, especially among older men. According to the Bureau of Labor Statistics, the early retirement trend will continue into the l990s and the labor force participation rates of people aged 65 ~d older will continue to decline. The decline In work activity among older persons is problematic from severe perspectives. One likely problem ~ the large number of unemployed older people in the population. This will create a significant increase in the burden of economic dependency. It ~ also likely that high rates of unemployment will have a negative effect on the quality of life of older adults because econorn~c security is important to independent living and self-esteem. For these reasons it ~ unportant to understand why work activity rates are declining among the elderly and aLso to identify strategies that delay early retirement awl encourage labor force participation of older adults. Some of the causes and remedies may have important human factors components. For example, if work becomes more difficult or less

24 HUMAN FACTORS RESEARCH NEI13DS FOR AN AGING POPULATION satisfying with age, this trend may suggest a lack of proper job and/or device design. High rates of unemployment among older people are due to a number of factors, including job discrimination, skill obsolescence, displacement, and discouragement. Despite the Age Discrimination in Employment Act, older workers are Recriminated against in many ways, including negative biases In performance ratings and being by- passed for promotions and retracing opportunities (Stagner, 1985~. For example, older people often fail to be selected for retraining pro- gram~ because of the incorrect stereotypes that they are unable to learn or are resistant to tramping. Where these forms of discrimina- tion are practiced, it may well be that they influence older workers to choose early retirement when, in more favorable circumstances, they might continue working. The Section to retire from the work force ~ very complex and influenced by a number of factors. Economists ant] other social ~ci- ent~ts have described the retirement Section as a process by which the older worker weighs the consequences of continuing to work against the consequences of electing to retire (e.g., Welford, 1976~. Two major chase of factors have been identified as influencing this Section: (1) individual factors financial resources, health status, attitudes toward work and retirement, and social support pressures and (2) institutional factors economic conditions, workplace con- ditions, employee policies, ~d public policy regulations. Of these factors, several studies have identified health and financial resources as the most Report ant (Robinson et al., 1985~. With respect to workplace factors, a survey of retiremen~age workers in two large organizations (McConnel, FIeisher, Usher, and Kaplan, 1980) found that 50 percent of all workers would remain employed if alterna- tives to the normal 8-hour workday were available. Such alternatives might include part-tune work or work at home via a computer. Iden- tifying further compensatory work strategies is a potential area for human factors research. The relationship between aging and performance in the work- place is complex. General aspects of employee performance include accident rates, absenteeism, turnover, grievances, and productivity. Regarding accidents, the data clearly indicate that older workers have lower rates than younger workers. However, older workers tend to remain off the job longer if they are injured. Absenteeism and turnover rates are also lower for older people, but this may be due,

HUMAN FACTORS PROBLEMS ASSOCL4TEID WITH AGING 25 at least in part, to the fact that they would find it difficult to secure another job (Stagmer, 1985~. Currently, data regarding aging and job performance are lim- ited, and the results are often ambiguous because of methodological shortcomings In data collection. As Czaja (1987) points out, many in- vestigatore rely on supervisors' ratings of performance, which may be unreliable if the raters are influenced by negative stereotypes about aging workers. Also, many of the studies are era - -sectional, compar- ~ng different cohorts at the same point in time; involve small sample sizes; and are restricted to certain types of jobs within limited oc- cupational categories. Most studies focus on unskilled or semiskilled industrial jobs, and there are few well-documented studies examining the performance of older adults at jobs that have a large information processing component, such ~ computer-interactive tasks. McElroy add Cascio (1989) present a comprehensive review of the literature regarding the relationship between age and job per- formance. They performed a meta~analysm of over 65 studies and conclucled that age and job performance are unrelated. However, they caution that most of the studies they examined were cross sectional and involved small samples. In addition, they suggest that there ~ a need for more research on the 5~ to 7~year-old age cohorts. As far as objective measures calf job performance are concerned, most of the research literature retread little, if any, basis for the w~despreacl belief that job performance declines with age (Sheppard, 1987~. The data that are available suggest that tasks involving heavy physical demands or those that are externally paced may be unhurt able for many older workers (Davis, 1985; Waldman and A`rolio, 1986~. However, these conclusions are general and not specific to particular jobs or occupations. What is lacking is a systematic body of knowledge that ties ag~relsted changes in skids and abilities to the skit requirements of jobs. Although there ~ an abundance of laboratory data that are potentially useful In understanding problems of aging and work, cau- tion must be exercised when generalizing from laboratory findings to predicting performance ~ real-worId settings (Salthouse, 1986~. Laboratory studies typically do not account for the effects of ex- perience or compensatory strategies that develop after consiclerable time is spent performing a job. For example, Salthouse (1984) ex- am~ned age differences in performance on two structurally similar tasks, which were a normal typing task and a choice/reaction-time

26 HUALAN FACTORS RESEARCH NEEDS FOR AN-4GING POPULATION task that required key-stroke responses to rapidly presented alph~u- meric characters. Strong age decrements in performance were found for the reaction-time task but not for the tr~n~cuption typing task. Salthouse speculates that the older typists employed a compensatory- anticipatory-proce~irlg strategy to overcome their slower perceptual motor processes. This type of strategy would be unlikely to develop in a laboratory setting where practice on a task ~ relatively limited. Salthouse (1987) pouts out that it ~ important to consider expe- rience when evaluating the potential significance of age differences in performance. The evidence suggests that adults of aD ages can ben- efit Tom experience ~d that in many activities increased age wiD correlate positively with the amount of relevant experience. How- ever, it is still not known In any detail what role experience plays with respect to common aging effect in cognitive and psychomotor performance. One possibility is that increased experience with a given activity somehow prevents age-related declines that would oth- erwise occur. Another possibility is that experience does not prevent declines but simply obscures or eliminates them by super~mpos~g experienc~related improvements. A third possible explanation is that experience provides for the development of compensatory mech- anisms that allow high leveb of performance to be m~ntamed in the face of deciding component abilities. Further research ~ needed to clarify the role of experience ~ connection with aging and perfor- mance. However, as Salthouse (1987) points out, despite the lack of knowledge regarding the specific eEect of experience on performance, it seems likely that a number of situations exult in which experience leads to an alteration ~ the manner ~ which complex activities are achieved, such that expected age impairments are either minirn~zed or eliminated. Of the many finings regarding age difference ~ performance, there are several that appear to be relevant to work activities. These include declines in sensory Unction and strength, a general slowing of behavior, and changes ~ perception and cognition. Specific examples of age ejects are discussed here in terms of potential implications for job activities, and these examples should serve to highlight needed research in the area of aging and work performance. The decline in average visual functioning with age ~ well doc- umented. In general, this decline is characterized by a reduction in the range of accommodation, first noticeable at the norms reading distance; a clistortion of color, especially in the blue region; a 1088 of light transmission, which produces significant change In the amount

HUMAN FACTORS PROBLEMS ASSOCIATED WITH AGING 27 of light impinging on the retina; a low of contrast Sensitivity; and a lo" of dynamic Virtual acuity (Leibow~tz al ~ Scialfa, 1987~. These changer in visual function have important implications for the perfor- maDce of work activities, because the majority of tasks contam a large visual component. However, data regarding the actual impact of age- relay changes ~ vision on the performance of jobs are limited. For example, in the microelectronics inclustry, visual inspection of chips and circuit boards ~ an important task, yet there are relatively few industrial data comparing age groups on Austrian inspection tyke. Sheehan and Drury (1971) found a slight age-related decIme ~ ability to discriminate between faulty m'd nonfaulty items; however, their sample population was small. E,rans (1951) reported no age eEects on inspection performance, and Jamieson (1966) showed a decrease in inspection error with age. It may be that experience and redundancy of perceptual cues compensate for viola] deficits. Similarly, there are few data available regarding the importance of age changes ~ derision for the performance of computer tasks. For example, older person may require larger screen characters to compensate for lomes in acuity or may have greater difficulty in ac- commodating to screen displays that are ~typical" for certain take. However, our general lack of knowledge in this area is substantiated by a report of the National Research Council 'I Committee on Vision, which recently sponsored a study on aging, work, and derision (Na- tional Research Council, 1987~. A major conclusion of the report of this study ~ that more research ~ needed on the relationship between aggregated changes in torsion and job performance. We also know that the elderly, as a group, have reduced" abilities in strength =d exertible force (strength being the capacity for pro- longed exertion or endurance, force being the intensity of maximum application of this strength). There is, on average, a Secrete in mum cle ma" with age, which results from 8 decrease both ~ the number and the size of muscle fibers. In addition, the average maximal car paucity of the cardio~rascular system to deliverer oxygen to the working muscle is reduced relatively early in the aging process. Translated into performance, there are rough estimates that by age 40 average muscle strength is about 95 percent of an earlier maximum in the late 20~; by age 50 it drops to about 85 percent; and by age 65 only 75 percent of the earlier output ~ stiD available, with further declines thereafter (Vitasalo, Era, I,eek}n en, "d Heikkinen, 1985~. However, these are population mean differences and there is a great deal of variability ~ different muscle groups, In types of muscular

28 HUMAN FACTORS RESEARCH N13EIDS FOR AN ACING POPULATION performance, and between m~ividuab. ~ addition, ejects of tra~n- ing and motivation can be considerable. ~ general, however, there is a clew decremental pattern wish aging. Venous laboratory studies are available that detail changes with age in the performance of spe- cific muscle groups as measured by dynamometer, and these findings have important implication for the performance of job activities (Stoudt, 1987) smce may tasks more lifting and carrying or ret quite stamina and endurance. Currently, we have general knowledge suggesting that these types of tasks may not be well suited for some older people, but we do not have detmied information on their actual performance of such tasks. There is currently some controversy regarding the locus of siow- i~g with age, and it ~ unclear whether it is primarily due to changes in the perceptual and motor systems or in centr~-processing systems. Nevertheless, one of the most reliable findings regarding aging ~ that there ~ a general slowing of behavior as age increases. This finding implies that older adults will be at a disadvantage if tasks require quick decision or rapidly paced activities. However, data Tom induce trial studies suggest that older people are not generally employed in such jobs (e.g., assembly work). The siowing-with-age phenomenon is highly significant in today's society, which is becoming increasingly automated. One potential consequence of automation is that mdivid- uab will lose control over their work rates and that t~ks will become machine paced. Since computers have the capability of controlling the rate of information flow, they allow tasks that were traditionally unpaced to become Maine paced. For some canes of tasks, such as data entry, computers often unpose tight externad control over the information-process~ng rate, thus making these types of tasks more difficult for older workers to perform. However, computer meth- ods Night be used to merease the flexibility of task pacing, thereby reducing, rather than increasing, the detrimental interactions with aging. To a large extent, su~ regulation of automation has been considered only from the perspective of job satisfaction as opposed to job performance. Although age changes in paced tasks have been obeer~red in laboratory and ability testing situations (Salthouse, 1985), most of the studies regarding pacing and age have been concerned with ~ndustrial-m~ufactur~g tasks. Few efforts have been directed at understanding the effects of aging on more complex information- processing requirements, such as those inherent in computer-interac- tive tasks (Czaja, 1986; Egan and Comes, 1985~.

EIUMAN FACTORS PROBLEMS ASSOCIATED WITH AGING 29 It Is unportant to determine whether the siow~ng-with-age effects constitute a unitary phenomenon or whether different task elements are variously affected. Such information is relevant both to apprm priate job placement of older workers and to proper redesign of tasks and equipment. Czaja (1987) has emphasized the importance of determining the extent to whim decreased response time can be compensated for by practice and experience or job redesign. It may be, for example, that older adults require alternative work schedules such ~ part-time work or different work/rest cycles; these options need to be evaluated. For some tasks a decline in speed may be offset by experience or extensive practice, but such compensation may incur a cost. Attempting to conform to a faster pace can en- hance stress, because sources of task strew include both intrinsic m~d perceived demand of a task. The elderly tend to be more cautious during task performance, emphasizing correct decisions and precision in their work. Tight external control of tasks would tend to defeat these compensatory strategies, thereby increasing the perceived de- mands of the task. There ~ insufficient understanding of how aging affects stress responses in such settings. Techniques need to be d~ developed that measure task strew and its effects and that are sensitive to age-related differences ~ physiological responses. The impact of age-related changes in capacity ~d perceptual processing on work performance also needs to be examined. The relationship between age aIld attentional capacity is not yet clear. According to the Attention deficit hypothesize (Hunt and Hertzog, 1981), attentions capabilities decline with age, and complex tasks that demand attention show more aggregated decline than simple tasks. However, Wickens, Braune, and Stokes (1987) suggest that support for this hypothesis is mixed. They used a tracking task tenth different versions of the Sternberg memory search- task ~d measured performance of different age groups under single-task and dual-task conditions. The results indicate a general decrease in information- proce~ng speed but little age-related difference in time-shar~g abil- ity. However, these results must be interpreted with some caution, as unfarnili~ laboratory tasks were used and the age range of the sample was restricted to a maximum of 60. Nevertheless, an impor- tant conclusion of Wickens et at. was that attentional capacity did not appear to change simultaneously across the age range examined. Their data are relevant to many types of work tasks, such as those found in aviation, computer use, and managerial activities. It Anti be useful, however, to examine the manifestation of attention effects for

30 HUMAN FACTORS RES1EARC~ NEEDS FOR AN AGING POPULATION a wicler variety of tasks with different combination of time sharing over a under age range. Egan and Gomez (1985) and Braune and Wickens (1985) also found that spatial cognition ~ ~mport~t to such teaks as text editing and piloting. There are substantial data medicating that spatial mem- ory declines with age. However, except for a few molated instances, decrements ~ spatial memory have not been examined ~ terms of everyday tasks and activities. Because spatial skim are ~n~rol~red a variety of jobs (requiring, for example, vehicle control or visual search), the extent of age changes In spatial cognition needs to be more fully understood ~ terms of job performance (Czaja, 1987~. There are several changes in perceptual abilities that may ales, be relevant to a ~rariet~r of work activities. These include declines ~ perceptual flexibility and speed of encoding. Older adults also have difficulty proce - mg complex or confusing stimuli and are more likely to experience interference from irrelevant or surplus information. These changes in perceptual processes are likely to be important elements In many occupational tasks, involving, for example, the use Of visual display terminals or inspection tasks (Czaj~, 1987~. For many tasks, environmental interventions, such as altering the level of ilinmination, may minimize the age-related effects of declimog torsion and perception. For example, ~ternati~re desigm for screen, workstation, or eyegI~es may also make it eager for older persons to use computer terminals. Yet, to date, there are Sufficient data on appropriate mter~rention strategies that could be unplemented ~ work situation. Another area in which insufficient research has been conducted is in the trait ing of older workers. Docurr~ented declines in cognition have often been based on situations where older people had limited opportunity for learning (Hulicka, 1967~. Severers investigators (e.g., Belbin and Shimmin, 1964) have shown that, if appropriate training strategies are used, age differences ~ performance can be reduced or eli~ninated. To date, there are only limited data available on task- specific training strategies that are appropriate for older learners and that benefit people of all age groups. It win also be useful to determine the extent to which providing tramping on component skids, such as visual search, benefits performance on t~ks such as · ~ — Inspection. In general, research attention to those aspects of work that bet come more difficult, led productive, or led sat~fymg with age could make a worthwhile contribution to the Prague of older workers who

HU~V FACTORS PROBLEMS ASSOCL4TED WITH AGING 31 remain employed and to the quality of their lives. As an exam- ple, it has been widely reported, and experimentally demonstrated, that certain kinds of tex~editing programs are much harder for older worker to learn than for younger workers (Ega;n and Gomez, 1985; Czaja, Joyce, and Hammond, 1988~. This is predominantly because the more complex a cognitive task, the greater the average deterioration with age. As a result of research into the problem of ag~appropriate text-editing programs, Egan and Gomez were able to identify p~ticuIsr aspects of the skin that were responsible for the observed age deficits "d to specify a design for a text editor that is operated with equal ease by old and young individuals. T}~0SPO1tTATION The Screwing ~llrnbers of older persons, particularly those who are very old and/or frail, will significantly affect the future of our transportation system. We c" anticipate more elderly people oh orating automobiles Ed a growing number of people who will need to use public transportation. Problems of restricted mobility are common Hong older adults, and their rate of tragic accidents is high. These facts powt to the need for applying human factors tech- niques to the study of transportation for an aging population. Ret search efforts should center around understanding exactly why older people hare difficulty driving; how changes in vision, cognition, and psychomotor skills contribute to these difficulties; and how these problems con be remedied through car and roadway design, prom thetics, driver trnining' and public policy. We also need information about how trains, subways, buses, airplanes, and terminals should be designed and managed to accommodate the needs of the elderly. ~ will be important to gather data on how to facilitate travel for older adults with respect to acce—mg arrival and departure information, handling baggage, any generally negotiating centers of public tramp portation. Similarly, we need data regarding the design of elevators, escalators, stairs, ~d walkways In public places. The next section will highlight some of the Hues surrounding aging and trar~sporta- tior`, but the focus will be on automobile driving because there is insufficient information on the use of other forms of transportation by the elderly. lo.

32 HUMAN FACTORS RESEARCH NI313DS FOR AN AGING POPU~TION Dri~mg In mobile, industrially advanced societies such as the United States, driving an automobile provides on-deman<1 transportation, a recreational outlet, a means to reach work, and, for the professional driver, work itself. The number of older drivers con U.S. roads add highways is already high and ~ increasing. For example, in California from 1974 to 1982 the proportion of individuab over 65 who were licensed to drive increased from 58 to 64 percent; at age 80, 31 percent (58 percent of men, 18 percent of women) held a driver's license (Califorma Department of Motor Vehicles, 1982~. As even more people move into old age, particularly the younger cohort of women who are likely to drive, the proportion of older persons on the road Anti increase greatly. Driving is the most common form of transportation for adults over 65. Unfortunately, on a mileage-driven basis, they are disprm portionately at risk for accidents. Figure 2 sumunarizes the accident characteristics of older drivers. Their overall auto accident rate is the highest of any age group over 24 (Planek, 1973; National Research Council, 1985b), and they are particularly likely to be involved in accidents and traffic citations involving failure to heed signs, to yield the right-o£way, or to turn safely (AlIgier, 1965~. Elderly drivers are involved ~ fewer singI - vehicle accidents than are young and m~ - aged persons, but they are involved in more two-vehicle accidents (Campbell, 1966~. Specific perceptual, psychomotor, cognitive, social, and physica-1 factors, as well as other factors including location, time of day, and type of vehicle, Al interact to produce a unique accident profile for the elderly driver, which will need to be determined by human factors research. Although almost 811 of the perceptual information used in driving ~ visual, efforts to relate vision (the most intensively re- searched of the sensory functions) to driving performance have been only moderately successful (Hills, 1980~. For example, the most com- mon vision tests used in licensing have little predictive power. This is not surprising given that driving represents a broad constellation of dynamicadly mteracti~re parallel and sequential processes that load differently on various visual functions. Discerning associations between vision and-driver performance is further complicated in the case of older drivers. In addition to the visual changes that are inevitable with age, there are differences in other variables, such as psychomotor speed and timing, vigilance, and attention, and in driving conditions, such as types of road,

BUNION FACTORS PROBLE~SASSOC~AT13ID WITH AGING 33 Number of miles drwen annually steadily decreases beyond age 50 and markedly drops at retirement. 2. Convictions: a. Rates decrease with age. b. Rates per ml/e show a slight increase at about age 70. 3. Accidents: a. Rates decrease with age until about 70 and then increase. b. Rates per ml/e sharply increase at about age 70. c. At age 75 rates per mile are as high as for teenagers. 4. Drwing Faults of Older Dryers: a. Persons over 65 are less likely to have accidents involving speed, drinking, following too closely, and improper passing than are younger people Bulgier, t965~. b. Persons over 65 are more likely to have accidents involving right-of-way, improper turning, and disregarding signals (AIlgier, t965~. c. Sign and signal, right-of-way, and turn violations per mile driven increase after age 69 (Huston and Janke, t 986~. d. Drying tasks that older drivers have difficulty with are changing lanes, merging, passing, backing, leaving from a parked position, and turning (PIanek and Overend, 1973; Wailer, House, and Stewart, 1977~. 5. Accident Characteristics of Older Dryers Versus Others (Nailer et al., 1977~: a. b. d. e. Slower speeds. At intersections. In daylight, in good weather, and an urban setting. Multivehicle rather than single vehicle. Merging or changing lanes, leaving from a parked position. FIGURE 2 Summary of Charactermtice of Accidents of Older Dri~re" tragic level, and time of day, that may contribute to the problems encountered by older drivers (Kline, 1987~. The following discussion will summarize what is known about how these variables influence driving behaviors and will suggest areas where additional research is needed.

34 HUMAN FACTORS RE:BE~RCH NEEDS FOR AN AGING POPUI~TtON Dynamic YsualAc~vi~. OVA was found to be associated w th driving records and with the frequency of accidents of bus and truck drivers (Burg, 1967; Henderson and Burg, 1973~. Visua/ Fief/. Severe fielc! loss in both eyes was associated with accident and conviction rates twice those of normal visual field Contras (Johnson and Keltner, 1983~. Static VisualActiw~. Dmers with severe visual impairment requiring bioptic telescopic lenses showed an increase in total and serious accident rates (Janke, 1986~. 4. Central Movement. There is some evidence relating central movement in depth to driving performance (Shiner, 1977~. Central angular movement was found to be related to acc~ent rates for dr vers over 65 for both day and night accidents but penpheral angular movement only for night accidents (Shiner, 1977~. 5. Glare Sensitivity. A small but sign ficant association with accents has been reported (Burg, 1967~. FIGURE 3 Summary of Visual Parameters "d Drying Source: Janke (1986) V.~wal Abilities end fig Because drilling is predominantly a visual task, it ~8 important to examine the relationship between the changes ~ Proud function that occur with age "d driving behavior. A sununary of Ecus! parameters and ciri~r~g is given in Figure 3. E—entially, there are a number of age~related char gee in vision that may affect driving performance. These include a decline ~ Visual acuity; a loss of contrast sensitivity; and changes In dark adaptation, dynamic Visual acuity, motion detection, and in the size of the Usual field and Usual search abilities (Kline, 1986~. Acm" Although static acuity is used most often by licensing agencies to determine visual fitness for driving (20/40 corrected vision being the common cutoff), the relatiombip between static acuity ar ~ accidents, while stronger for older drivers (Hilb and Burg, 1977), is not a robust one. In the human foveal-focal type of visual system, acuity is only

HU"4N FACTORS PROBLEMS ASSO~LAT23D WIT7I AGING 35 the visual field. The visual system did not evolve for driving, in which important objects often appear at may Ogles. The art of ~iv~g thus depends on complex control of eye movements in order to look ~ the right place(~) at the right tune, usually to detect objects moving relative to the Denver. For this reason research on the extent of visual field and visual search ability with moving stimuli would likely yield better predictors of driving performance than the current tests of acuity. Nevertheless, there still exists a need to establish more clearly how static acuity is related to driving skill, especially for older Snorers, given that static acuity testing ~ likely to remam the common screening method for some tune. It may also be valuable to investigate the relationship of low-cor~trast acuity to driving performance. Contrast Sonnitwit~ Function A cursory examination of driving suggests that visual spatial abilities may be critical to driving performance, since it seems likely that such skim are important with respect to the detection of road- way signals or signs. By assessing the visibility of objects varying in size, the contrast sensitivity function (CSF) appears to profile a more sensitive statement of spatial vision abilities than does simple acuity. I.ittle systematic attention, however, has been given to the spatial frequency characteristics of the signs and signals to which drivers (or pedestnans) may need to respond quickly. It is also likely that some driving any work tasks depend heavily on sensitivity to intermediate spatial frequencies, which can only be ame~ed by mew sures of contrast sensitivity. However, the diagnostic value of the CSF for such tasks h" yet to be validated by research. Dynamic V~1 Acuity and Motion Detection Dynamic Virtual acuity (DVA), which is the ability to detect detail a moving target, shows a progressive decIme with age (Reading, 1972) and appears to be related to driving performance, especially for older drivers (Hi~ urn Burg, 1977~. Hills (1980) has reported that older drivers me likely to undereats ate the angular precocity of high-speed vehicles, and Henderson and Burg (1974) have shown that the angular motion threshold correlates tenth accident involvement (at least in younger subjects). These data emphasize the need to attend to dynamic components ~ deriving measures of visual fitness

36 HUMAN FACTORS RESI3ARCH NEEDS FOR AN AGING POPULATIOI'{ or in assessing the design adequacy of roadway signs, tragic signs, displays, and markers. Currently there is no adequate measure of DVA In use by practitioners such as those who measure "driving fitness, although recommendations to that effect have been made (Scialfa, Kline, Lyman, and Ko~nick, 1987~. vimal Field Another variable that appears to be unport ant to driving ~ the size of the visual field. It affects the ability to detect vehicles or pedestrians on the highway and road markers or signs. The data indicate that effective visual field size is reduced in old age (e.g., Barrington, 1964; Wolf, 1967~. Some of this reduction may be due to optic media light attenuation (Weale, 1963~. Early investigations showed little relationship between visual field and accident rate (e.g., Council and Allen, 1974), even for drivers over 65 (Hilis and Burg, 19773. However, when Johnson and Keltner (1983) compared visual fields with the Year driving records of 10,000 volunteer license appli- cants, they found that drivers with binocular field lom had accident and conviction rates double that of an age- and gender-matched con- tro} group. Furthermore, the incidence of visual field loss was much higher ~ drivers over 65 (13 percent) than In those aged 16 60 (3-3.5 percent). To compound the difficulty, over half of those with vu field loss reported that they were unaware of it. These data suggest that more research ~ needed to ebonize the relationship between size of the visual field and driving performance. Visual field research that systematically varies target size, luminance, wavelength, con- tr~t, and temporal characteristics might yield screening and design criteria that would be especially useful for licensing older drivers. Distance Perception The ability to judge depth does appear to decline in old age (Hoff- man, Price, Garrett, and Rothstem, 1959; Bed, Wolf, and Bernho~z, 1972) and may contribute to the increase in right-o£way accidents experienced by older drivers. A recent simulation study (Scialfa et al., 1987) of drivers' ability to judge the speed and distance of an approaching car found that the older subjects provided dispropor- tionately high estimates of the closing distance. These simulation data suggest that, on average, older drivers would perceive it safer to enter or cross the lane of ~ approaching car than would younger

HUMAN lRi`4CTORS PROBLEMS ASSOCL4T13D WITH AGING 37 drivers in identical circumstances. More ecolog~caDy void research might be profitably directed to ~letermining age differences in dim tance perception under actual rather than simulated circumstances. Dark Adaptation Another aspect of visual functioning that may be critical to driving performance, and that declines with age, is dark adaptation. The literature suggests that older individuals do not adapt as weD to lowered leveb of ill nation as do younger adults. This may explain why it is especisily difficult for older people to Ante at night, under low lever of illumination. Perhaps some of the problems associated with the loss in adaptation abilities could be alleviated by changing highway illumination, car headlights, or automobile control panels or by driver training that emphasizes better compensatory strategies. These are areas to which human factors research could make significant contributions. vima] SearEh One of the major perceptual tasks of a driver is to sort out ~d favor critical stimuli at the expense of lem critical ones, a task often termed "visual search. Evidence suggests that visual search effectiveness is frequently imp aired in -older persons (Rackoff, 1975), especially if the display requires the processing of unfamiliar stimu- lus configurations (Prude and Hoyer, 1981) such as plight occur in environments new to the driver. In fact, for certain types of accidents and for drivers over 50, visual search pattern does appear to relate to accident involvement (Shmar, 19773. In a related study, Sekuler and Ball (1986) found that although young and old observers were comparable in localizing targets in the near periphery (at 5, 10, and 15 degrees extra£ove~ly), older observers were much worse at this task when the same target was surrounded by other stimuli. Scialfa, Kline, and Lyman (1987) have also reported evidence medicating a restriction with age ~ the useful field of view. On an optimistic note, Sekuler and BaD also found that even modest practice significantly reduced the error rate for older subjects. On the face of it, tasks such as this, in which the observer must respond to a stimulus embedded in a more complex scene, would seem to be a better approximation of the visual demands of driving arid other daily tasks than are the measures that have commonly been used, such as clinically measured

38 ~U]L4N FACTORS RE;SE~RC}I NEEDS FOR AN AGING POPUI~lION visual fields. However, this contention should be tested through further investigation. [ightmg and living The design of highway illumination systems and automobile con- tro} paneb may influence the ~nv~g performance of older adults. There are normal age-related changes in the optic media of the eye that attenuate, scatter, and alter the spectra composition of incident light, contributing to age-related losses ~ acuity, sensitivity, and task performance that are particularly evident under condition of poor illumination (Kline and Schieber, 1985~. Retma] iDuminance ~ the average 60~year-old eye has been estimated to be about one-third that of its 20~year-old counterpart (Weale, 1961~. Weston (1949) demonstrated that increases ~ target iBum~nation produced greater improvements in acuity (as measured by Landolt gap identification) in older persom than in younger ones. Increased contrast can also markedly Reprove the target letter identification perforTn~ce of older persons (Blackwell and BlackweD, 1971~. One of the visual problem most frequently reported by older people is that of inadequate illumination (Koenik, Widow, Kline, Rasinski, and Sekuler, 1988~. The actual level at which problems of illumination occur for people of different ages across different tasks (e.g., way finding or sign reading) needs to be identified by future research. One element of such a research program might be to determine the extent to which task performance can be ether ced by changes in lighting conditions. Beyond some minimum level the quality of illumination (e.g., direction, wavelength) ~ as ~mport~t as its quantity. For example, older people tend to be much more disadvantaged by susceptibility to glare (e.g., Burg, 1967), such as that caused by the headlights of an oncoming car, and are slower to recoverer from it. Although Burg (1967) did not observe a relationship between glare recovery and safety record, it seems reasonable to suggest that the contrast reduction effects of glare could be severe for older persons under conditions of reduced visibility (e.g., driving ~ the dark, ram, or fog). In designing vehicle lights the need to enhance visibility by max- irni~ng illumination must be badanced against the need to avoid problems of glare, both from oncoming and following hea~ighte. For any given light source the amount that ends up as glare wiD be

HU]L4N FACTORS PROBLEMS ASSOCL4TEI) WIT7I AGING 39 affected by weather and ambient lighting conditions (e.g., street or runway lights). Little research h" been carried out to determine the effects of subh glare on older persons under these re~-worId conditioIls (Pulling, Wolf, Sturgis, Vailiancourt, ~d Dolliver, 1980~. The spectral characteristics of light may also be important in determining visibility arid, therefore, the visual acuity of older people. Although the tradition of concentrating a ~acmp'8 energy in the yellow- green region of the spectrum increases its lur~iinance, it may also have negative side effects on color rendering (Boyce and Simons, 1977) snd visual acuity add fatigue (Maas, Jayson, and Kleiber, 1974~. Additional study will be necessary to accurately amess the impact of the spectral characteristics of light on specific transportation task performance, such as scene recognition, target detection, and sign, marker, and instrument reading. signs, Marled, Dimples, and Warn mge Signs, markers, ~d warnings are effective in communicating their content only to the extent that they are both conspicuous art d legible. In the operation calf moving vehicles these characteristics also determine how much response distance is provided the operator. A surrey by Yee (1985) revealed that 25 percent of older persom report diflicult3~ reading sign. The reasons given most frequently for this difflcult~r were Sign placement, inadequate size, clarity of lettering, and cI=ity of content. Although the 2.5~second minimum perception-reaction time in- tenral specified ~ the American Association of State Highway Awry portation Official' manual (1984) for hazard signs may be adequate for many older dri~rere (Oboe and Sink, 1986), this might not be the case for some drivers who are very old; when operating under poor conditions; or when si~ are not conspicuous because of their placement, brightness, or contrast. The reduction with age in retinal iDu~nination interacts most Aversely with poor lighting conditions, such aslow contrast, glare,shadow,ordimlight. Sivak, Olson, and Pastalan (1981) found that at night older drivers and p~engere in moving cars could report "formation from standard signs at only one-half the distance of younger persons. Even if visibility were not at msue, the relative sIowne" of older operators In response speed and problem solving in such circumstances might well call for a longer minimum perception-reaction time interval. This msue might best be addressed by research that assesses the response adequacy of very

40 HUMAN FACTORS REIS13ARCH NERDS FOR AN AGING POPULATION old or frail persons to signs/markers that vary In level of complexity, corl~picuity, and legibility under both normal and degraded viewing conditions. Image-proce=~ng techniques might also provide a pow- erful means for unproving the design of signs and other information displays. ~ driving, effective guidance and tracking depend on both nat- urally occurring stimuli (e.g., contrasts In color, shape, add texture; curbs and barriers, pavement striping). It ~ clear that better delin- eation of roadways does unpro~re safety: highways with centerlines are safer than those without; there are fewer accidents on highways with raped pavement markers than those with centerlines; and the addition of edge lines lowers accident rates still further (Schwab and Capelle, 1979~. However, the eject of such delineation or naturalistic cues on the performance of older drivers has yet to be investigated. Psychomotor Factors Id addition to visual factors, psychomotor skills are also irnpor- tant to driving behavior. Reaction time is a critical component of driving. The driver does not control either the speed of other vehicles or the sudden appearance of a pedestrian, but he or she still must respond appropriately. Furthermore, the length of time that visual information is present (e.g., on signs or warnings) may be limited. ~ addition, the more rapidly a stimulus moves or changes, the more difficult it is, especially for older persons, to discriminate its detain. Visual-cognitive processes, including directing attention to different parts of the situation, may not be rapid enough to allow an effective response logon and Sivak, 1986~. Each of the foregoing demands is related to ~ ability that has, on average, been found to decline with age, and many researchers view behavioral slowing as a manifestation of a primary age change (Planek and Fowler, 19713. Speed ~ also relevant to transportation tasks other than driv- ing. For example, the Manual on Uniform Marc Control Devices (Federal Highway Adm~n~tration, 1978), ~ determining the pede~ trian clearance interval, assumes pedestrian walking speed to be 4 feet per second. It ~ not clear that this standard provides frail or very old pedestrians with adequate time to make street crossings nor ~ such a speed calculation necessarily appropriate ~ the design of public transportation terminal and travel connection schedules for older persons. Human factors research in this area would prey sumably include task analyses of characteristic transportation tasks

HUA~J FACTORS PROBLEMS ASSOCIATE WITH AGING 41 ~d would be useful In the selection of Reprices ~d personnel for the improvement of the travel environment and for tommy. Compensation and Train mg Very little is known about how age-related behavioral changes affect driver or pedestrian skills, what behavioral functions are im- port~t to such skins, or what kind of compensation older persons make to offset age-related functional impairments. Older drivers are less likely to drive at night, perhaps in response to the difficulties they have under conditions of low illumination. They are also much more likely than younger drivers to reduce their speed ~ response to signs requesting it, such as In construction and maintenance zones (Gardener and Roughed, 1983~. In addition, they use a greater fol- lo~nng distance than younger drivers. These responses may be, at least in part, attempts to compensate for their diminished response speed. Presumably, older pedestrians are also capable of making age-related compensations. With regard to the implementation of traming or retraining, while the performance of older persons is not necessarily facilitated by the use of traditional vocational training strategies, their per- formance can be improved by using more active problem-solving methods (Czaja, 1986~. Although the extent to which this and other approaches can increase the safety and mobility of older drivers, trav- elers, or pedestrians h" yet to be determined, retraining represents a promusing avenue of research. We need to know more about com- pensations, how they interact with basic age changes, and the degree to which such strategies can be effectively taught. Other :Farms of ~an~ortation Because older adults must so often depend on others for trance portation, the lack of data in this area represents an important gap in human factors knowledge. Current transportation systems seem to be problematic for the elderly (Carp, 1979), and data indicate, for example, that older people frequently have difficulty getting to such places as grocery stores or doctors' offices (Czaja et al., 1988) because of transportation problems. What ~ needed are descriptive data regarding the types of transportation older people use, why they choose these forms of transportation, and what kinds of problems they encounter. A task

42 HUMAN FACTORS RESEARCH NE13DS FOR AN AGING POPULATION analyst of ~ranou~ forms of transportation that specifies demand associated with these system ~ also In order. Such ~ aneurysm would provide a detailed specification of problems add would enable us to develop and test alternative design solutions. This research should not be restricted to automobiles, buses, tzmns, "d airplanes but should also include walkways, stairs, execrators, art d escalators. l~portar t questions might center on, for example, specifying approve priate types of handrail for buses and trains, identifying the most effective display panels and door speeds for elevators, snd identifying effective systems for baggage handling and ~nterterm~nal connection at airports. These are only a few of the are" that need human factors attention. There are clear and pressing gaps in our knowledge of age differ- ences in the performance of tasks related to transportation. Yet, at present, v~rtu~y no provision is made in human factors engineering guidelines for age-related changes. As a consequence we have little current ability to develop ~ transportation system that wiD effectively support the needs of the elderly, especially those who are very old or frail. As information systems in terminate, vehicles, ~d roadways become more complex and responsive in "real time, this problem will be aggravated. Critical to its alleviation Will be analyses of the tasks that operators and travelers must carry out; identification of the tasks that tax the functional capacity of the impaired, but poten- tiaDy mobile, older person; allocation of such tasks to user-friendly systems; and development and implementation of human factors engmeer~g standard that recognize that a significant proportion of our population ~ already elderly. What ~ currently needed are systematic studies of transportation t~ks to better understand the difficulties older people experience in these settings. Rese~ch to cir- cumvent or eliminate reported and observed problems can then be initiated. COMMUNICATION The issue of communication and older adults has been hugely neglected within the research Roman. Efforts hare been limited to the study of speech comprehension as a function of hearing lo" =d examination of I=guage skills across adulthood. In addition, there has been some work In the area of perception and comprehension of text and, to a lemer extent, interaction with Engage system. Most of this work has been conducted in the laboratory with few real-world

NUALlN FACTORS PROBLEIMSASSOCILATED WITlIAGING 43 applications. What ~ lacking ~ a body of knowledge about how aging is related to the communication skim (both sending and receiving messages) of older adults and how effectively older adults are able to interact vnth communication technologies such as the telephone or computer. The topic of communication is of critical importance Once older people often have restricted mobility and thus need to rely on comrnuDicatiork technologies to provide finks to the outside world. However, currently we know little about the ability of older people to use these technologies. The common lo" of auditory acuity that occurs with age is ret ferred to as presbycusis. Some of the characteristics of this syndrome include impairment of speech discrimination ability, decreased ability to understand Extort or nomy speech, add decreased ability to ret call long spoken sentences (Olsho, Harkins, and Lenhardt, 1985~. AD of these symptoms decrease the ability of an m~ividual to comrnuni- cate effectively. Currently a large portion of the elderly population (75 percent of those 75 and over) supers from this disorder to some degree. Research clearly medicates that speech intelligibility declines progressively after age 50. Even if elderly listeners are tested under ideal conditions, a quiet environment with degraded speech, there is a small but measurable decline in speech comprehension. It is rare that listening conditions ~ the real world are ideal, which suggests that for the most part older adults are at a disadvantage tenth respect to speech communication. However, it ~ not known how this decline in speech perception effects tin older person 'a daily functioning. For examples although presbycusis would appear to make one especially vulnerable to poor-quality and otherwise unfavorable noise environ- ments frequently encountered, we lack detailed knowledge of their effect on the ability of older people to interact tenth telephone or speech syntheses systems. Another unportant area of research ~ this regard is interven- tion, that is, identifying ways to compensate for the lo" of speech perception. There are four are" where human factors engineering can mter~rene to improve speech comprehension in the elderly: (1) the sender~eveloping speech systems that account for decrements in audition (e.g., loss of sensitivity to high-fiequency components); (2) the I~tener~e~reloping training strategies that increase compre- hension; (3) the auditory signal~e~reloping more effective hewing aids; and (4) the environment~eveloping design strategies for the acoustic environment to facilitate speech comprehension. The start- ing point for any intervention research ~ to understand how the

44 HUA~4N FACTORS RE;SElARCN WEDS FOR AN AGING POPU~UON age-related decline in audition affects an older person's ability to communicate on a daily bow. The lo" of visual function may also impact on an older person's ability to communicate effectively because large amounts of ~nforma- tion are transmitted via printed and televised words and pictures. Factors that may affect an individual's ability to read text include a loss of visual acuity, declines ~ aCcornrnodation and contrast sensitiv- ity, and changes in visual search. Changes in ~nformation-proce~sing abilities, such as difficulty discriminating between relevant and irrel- ev~t stimuli, may also reduce an older person's ability to read text. As is the case with hearing, we need a better understanding of how changes In visual perception affect older people's daily functioning. Possible areas of impact include reading newsprint and signs and the ability to interact with television and computer technology. The computer represents a potentially very useful too! for older adults. It can be used for communication via electronic mm] networks, for education, as a memory aid, and as an information source. However, this is only true if systems are designed such that they can be used by older people. For example, although there has been a great deal of research examining visual functioning and computer use, age has been largely neglected as a variable of interest. Important questions for human factors research center around character size, shape, and color; amount of contrast; and appropriate leveb of illumination for perforr:iing these types of tasks. We believe that what is most needed at this tune are systematic studies of communication tasks ~ order to identify the problems that older people experience. Research on ways to circumvent these problems will then become the appropnate and subsequent focus of human factors research. SAF1:TY AND SECURITY It is appropriate that safety and security, traditional issues in human factors, should be emphasized when discussing research direc- tions for human factors and aging because older people are especially vulnerable to the consequences of accidents. The fatality rate, length of hospitalization, and days of disability and restricted activity due to injury are greater for older than for younger adults. In addition, safety and security are important with respect to older individuab' sense of control over their environments and their continued ability

HAN FACTORS PROBLEMS ASSOCL4TED WITH AGING 45 sense of control over their environments and their continued ability to function independently. Finally, the fear of accidents or victim- ization may limit the activity choices of older people, causing them to modify or restrict their Iif - styles. Although details concerning safety/accidents are limited for older adults (with the possible exception of falls and auto accidents3, and the data that are available are largely epideniiological In nature, we can make some useful observations and draw some tentative con- clusions. Considering the demographics of injuries, older people have relatively low accident-frequency rates compared with other age groups but higher disability and fatality rates (Singleton, 1975~. Among persons aged 6~74, accidents rank fifth as a leading cause of death. In 1978, 22.9 percent of all fatal injuries were of persons aged 65 and over, even though this group represented only 11 percent of the total population. People from this age group who have incurred an accidental injury have, on average, 2.S times the total number of days of restricted activity per injury and 2.9 tunes the number of days confined to bed than do 6 to 16 year olds. In addition, older accident victims typically have a poorer recovery and a greater Bum ceptibility to complications following injury than do younger people (Sterns et al., 1985~. These data demonstrate the magnitude of the aging and accident problem. Domestic and Com~nnnit~r Elrv~onments The vast majority of older people live in private residences. It is clear from the literature that the ability to live independently is critically important to older people. However, it is also the case that living independently ~ often problematic for older people and their rate of home accidents is high. The World Health Organization estimates that each year 5 to 10 percent of the population in developed countries suffers significant in- jury In domestic accidents. The elderly, children, and housewives are overrepresented in home accidents, no doubt redecting their greater exposure. In fact, persons aged 65 ~d over account for approxi- matelv 43 Percent of Al home fatalities. The character of exposure _ i, ~ _ _ _ ~ ~ I 1 ~ _'1 ~ '_ AL _ ~ _ _ 2~ ~ _~1~ 1 ~~~ .,~1~. _~ ~ to accidental Injury WItDm the Dome Is proDaoly quall~a~l~rely aria quantitatively quite different for older people (Neutra and McFar- I~d, 19723. For example, older individuals me more likely to live in old and substandard housing, to have strong medications In the home, to be users of various medical devices, and to use manual

46 If UA"N FACTORS SEARCH NEEDS FOR AN AGING POPUI~TION activities, motivation, "d functional capabilities, it ~ reasonable to expect that there would be differences from other segments of the population in the type and location of domestic accidents. Table ~ presents data on the frequency of accidents for different environmental features and products, the percentage of injured per- sons who are over 65, =d the percentage of injured persom who are hospitalized. These data are Tom the 1985 Product Summary Re- port of the National Electronic Injury Sur~reiDa~ce System (NElSS) of the Consumer Products Commission (CPSC). The NETSS system is ~ national data collection system that gather daily information about produc~related injuries that require treatment in emergency rooms. The selection in this table Tom the hundreds of products Bated in the CPSC report ~ based on overrepresentation of the el- derly; size of the national estimate ~d, to a lemer extent, on the severity of ~jury; and on consistency with the 1978 NElSS Product Summary Report (Jones, Smith, "d Small, 1983~. The high incidence of injury associated with stairs and Steps, floors ~d floor coverings, bathtubs and showers, and ladders ~d stools reflects the prevalence of falls that older people experience. In fact, few represent the most frequent nontr~n~portation-related accident occurring among older adults. They are the leading cause of Al home fatalities. For individuals over 75, falls account for more than one-half of Al injures, with women more ~ruinerable than men. For this group, deaths from falls surpass deaths from transportation- related accidents. ~ a quantitative aD~y~i8 of NEWS data for the yews 197~ 1980, Czaja et al. (1987) identified the 49 most hazardous products and most costly accidents for people over 55. The most hazardous products were floors add floor coverage and stairs and steps, which accounted for 41 percent of all injuries related to these 49 products. Other hazardous domestic products were foods, chairs, bed, ladders, lawn mowers, bathtubs, and showers. Falls were identified as the most prevalent type of accident. These results are competent with those reported by Smith (1987~. In a large study of accidents and the elderly in England, Pru~ham and Evans (1981) also reported that falb are prevalent among older people. In their sample 47 percent of the people had fallen indoors, 33 percent outdoors, and 20 percent ~ both places. Falb that occur outdoors are typically attributed to wet or slippery surfaces or uneven terrain. Burns me also common among older people. In fact, burns ~d

Hl~J FACTORS PROTEINS ASSOCIATED WI~ AGING TABLE 8 Frequency of Product-Assomated Injuries for Elderly Persons for Selected Locations Environmental Location Nationala Percentb Percents Estimate 65+ Hospitalized Stairs and steps 768,848 12.1 4.9 Floore and floor coverings 620,894 25.4 10.9 Runners, throw rugs, door mats 11,188 39.2 13.6 Rugs and carpets 41,263 27.9 11.4 Beds (not specified) 201,067 15.6 6.S Sheets or pillowcases 2,137 18.9 10.7 Blankets 2,023 21.8 3.9 Bathtubs and showers 100,358 16.1 4.5 Bath and shower enclosures 1S,279 17.5 7.1 Toilets 21,047 31.S 6.1 Chairs (not specifiedj 169,`6S 17.3 4.7 Ladders (not specified) 70,832 16.2 10.7 Stepladders 9,704 85.9 6.5 Stools 17,991 22.0 6.1 Step stools `,794 34.2 . 20.1 Wheelchairs 21,296 59.9 12.8 Crutches, canes, Rallier 18,280 64.7 23.S Benches and table saws 17,283 18.5 4.9 Eyeglasses 1S,519 18.5 2.8 Elevator 10,626 22.8 4.9 Estimate for U.S. population based on sample. ~Percentage of persons 65 or older in sample population. CPercent hospitalized from total sample--reflects severity. Source: Data from National Electronic Injury Surveillance System, 1985. 47 other consequences of fire rank third ~ a cause of death In the 65+ age group. Cooking, smoking, using hot water, "d accidentally turning on and failing to turn off appliances are activities thought to lead to accidental borne. Czaja, H - nmond, Blascovich, and Swede (1986) found that products producing the most severe injuries were fire related genera fires at home, smoking materials, Ed clothing. This study also reported that scalds from hot water were common among older persons.

48 HEN FACTOR ~S=RC~ ==S FOR ~ AGING POP UNWON Poisanmg Ingestion of toxic dosages of medication now ranks among the three most prevalent home accidents. Only a portion of there oc- cu~Tences in adults ~d older children me accidentsI, with many attributable to unintentional self-pomon~g. The elderly are apt to be taking several highly potent drugs, to be physiologically ~ensi- tive to their effects and their interaction with other drugs, to have disabilities, and to live in an environment conducive to medication error. Labeling, lighting, and dose/inter~ral management have been suggested as predisposing factors. Fa~letti (1984) has suggested that medication management ~ a fruitful area for the application of hu- man factors technology, ~ Creaky demonstrated ~ devices such as audible reminder systems and self-stable containers designed for the older hand and eye. Accidental Injuries to ElderI~r Pati~ts Accidental injuries to elderly patients pose a growing problem for hospital, nursing homes, and other residential care facilities (New- man, 1985~. FaDs and fires are especially severe problems. The Aetna Life and Casualty Company (1981) reported that between 1976 ~d 1981 falls were a factor in 20 percent of all claims filed against their insured hospit ads; 75 percent of the fans occurred ~ patients' rooms. Unique health/safety problems and solutions exist for the dementia patient. The high incidence of mental decline and confusion among the institutionalized elderly powts to a critical role for technology. For example, a passive alarm system (Ambul~m) that signals when a patient a - umes a seated position on the edge of the bed h" been tested and found successful ~ reducing accidents and decreasing the need for restraint In confused patients. The limited research on older patients who fan or experience other accidental injuries has been largely anecdotal, and little human factors research has been done for any age in the medicad setting. The frequency of accidents and high accident fatalities for older people at home and in i~titaltional environments provide a com- pelling target for human factors research in this area. To date, studies of the elderly have been descnptive. They offer some gen- eral insight into the environmental features of accident scenarios and some general guidelines for home and building modifications. For example, limited work has been done on the cause of fails and on the development of intervention strategies. However, little is known

HUMAN FACTORS PROBLEMS ASSOOlAT~ WITH AGING 49 about the specific mechanisms that produce fads ~ the elderly. It is clear that many factors interact to increase the risk of falling among older people, but a better understanding of the causal nature of this problem ~ needed before effective methods of intervention can be developed. Human factors reteach in this area has focused prunar- fly on the design of stairs and railings (e.g., Archea, Collins, and Stahl, 1979; Pam, 1984) and the work of Alessi, Brill, and associates (1978) provides an amemment of the safety environment of stairs. Using data available from the Consumer Products Safety Commis- sion and the National Bureau of Standards, Alessi et al. identified 12 stair accident scenarios involving about 82 percent of Al cases. Table 9 presents a summary of their findings. Types 1 (overstepping) and 7 (Ioss of balance) were the only ones significantly related to older persons. In a farther aneurysm of their NEISS data, Czaja and Drury (1986) developed 8 detailed analysis of six of the most hazardous products for persons over 55. In p~ticul=, they reported on a detailed human factors analysis of bathtubs/showers. The most frequent causes of in- jury were slips, fans, and strikes aghast objects. The primary tasks associated with these accidents were getting into the tub/shower, washing, and getting out of the tub/shower. Dazzlers and loss of balance were experienced Frequently. Scaldings from hot water in the tub/shower were the second major type of accident. Extension of detailed environmental analyses, such ~ the Czaja et al. (1986) ~d Alessi et al. (1978) studies, neecIs to be focused on the elderly add applied to other specific hazardous areas in the home and cornmu- nity. Planek (1982) asserts that successes in home accident control have occurred in narrowly defined, aIld therefore, more manageable problem areas. nIustrations of this pout are drug-conta~ner design, prevention of refrigerator suffocation, and flame-retardant sleepwear for children. The example of studies on fads (Archea, Carson, Mar- gulp, and Carson, 1978), the design of stairs (Alessi et al., 1978), and the analysis of NElSS home accident data (Czaja et al., 1986) might serve as models for specific product/accident analysis =d for evaluation of other product/environment categories. Work ~v~ronment The ratio of workers aged 45 =d over to the general working population has Secreted steadily during the last 30 yews. This may account in part for the lack of pressure to evaluate safety or accident

50 LUMEN FACTOR ITCH IS FOR ~ AGNG POPUM~ON TABLE 9 Types of Stairway Accidents Percontage Stair Cause or Event Aeadents Victims Misjudged tread depth while 19.0 descending Obstructed view while descending 10.9 Descending: caught heel on 9.0 nosing; ascending: foot did not clear nosing Climbed store or descended 6.S in Darlene" Foot placed on nosing; carpet 6.5 elf" Wet or icy stab Lost balance: handrail inadequate Distracted by change of visual (or other) environment Adult women in a hurry; the elderly; persons with poor eyesight; persons under the influence of alcohol or other drugs (medicatione) Adult women carrying children or objeeb, often in dark unable to activate light switch Adult women in high heels children ascending Anyone: often unfamiliar places Anyone S.7 Anyone S.7. Anyone, but Specially elderly and disabled S.0 Anyone Treads too shallow d.2 People with large feet, heavy shoes, or, in extremes, most adults Irregular treacle or rmere or S.8 Anyone any iregulanty Small flight (1 or 2 neer) in 2.9 Anyone unusual place griddle of Rays Objects on stairs 2.9 Anyone Source: Jones, Smith, and Small (19793.

HUMAN FACTORS PROBINGS ASSOCIATED WITH AGING 51 prevention for this age group. Whether occupational safety and age are seen as a high-prionty research issue for the future may depend on how we define the older worker. The National Commission for Employment Policy kiss identified older workers as persons 45 years of age and older. About 30 minion people, 45 64, are currently employed, and this figure is expected to grow to 45 nonillion by the year 2000. At the same time a decrease in the inflow of younger workers may compel older employees to remain longer in high-risk tasks. Morrison (1984) argues that the older m~le-aged worker wiD be the dominant labor force mue In the coming yea=. While a great deal of research on occupational accidents has been done, some of it in the area of human factors safety, studies ~d descriptive data on the oilier m~e-agecI employee and the elderly employee are limited. In general, the age-related injury pattern at work parallels that In other environments; as age increases, the frequency of injury decreases "d severity increases, with falls being an especially severe threat to the older worker (Root, 1981~. The study by Root, based on approximately ~ minion worker compensation records, found that injury rates dropped regularly until age 64 and more sharply for persons over 65. ~ general, thin trend was independent of the kind of industry ~n~rol~red. Relative to occupational accidents, we need to know the specific jobs, task demands, equipment, "d environmental features present when the older worker is mvol~red. Unfortunately, information is not readily available for the older population. ~ the Czaja et al. (1986) study of NElSS data, industrial equipment was among the 49 most hazardous products for persons over 55 "d "non g the top 10 most hazardous for persons 55~4. Ginger, Dispenziere, and Emenberg (1984) hypothesized that a speed job (sewing machine operator) versus a skis job (quality control examiner) would-~fluence the accident rates of older workers (mean age—57), but no differences were found. It h" been suggested that older workers hare fewer acciclents that result from carelessness or poor judgment and more accidents that result from berg le" successful at escaping hazards. Recently, Shahani (1987), ~ analyzing 7,131 incidents at Shed Oil, found that accidents tended to decre~e until about age 51 Ad then increased. This age-related pattern was similar across different families of jobs up to age 60, but at the older ages (61+) the accident rate was a function of the kind of job.

52 HUMAN FACTORS RESEARCH NEEDS FOR AN AGING POPULATION Unique kmds of occupational accidents associated with the el- derly are those experienced by the family or human services care- giver. For example, while most heavy lifting has been engineered out of other jobs, this is not the case in the human services industry. This industry is reported to have the highest percentage of overexertion injuries of any major industry (62 percent of work injuries), a sizable proportion of which could Groove care of the elderly (National Insti- tute for Occupational Safety add Health, 19813. The prevalence of low back pain has been shown to be significant in the nursing prm fession. Of similar concern are overexertion injuries ~d other safety problems for individual family caregivers, who therrmelves may be aging, under strew, and tenth little opportunity for relief. Basic shifts In nationad employment patterns have token place in the last 30 years. These include rapid growth in white-color jobs (professional, technical, managerial, and service); a proportionate decline in blue-collar jobs; increased numbers of women (inCluding older women); and increased participation of specific ethnic groups. A parallel change has been occurring in new work technologies, such as numerical control, robotics, flexible manufacturing, and computer- a~ded design. It ~ not clear what these changes In technology and the composition of the work force may mean for safety Dues ~ an aging population. Transportation ]5nv~onment The maintenance of independence and quality of life for older persons is heavily dependent on access to adequate transportation. Loss of personal transportation and inadequate public transporta- tion, or a transportation handicap, lead to an increased requirement for family and public support for the elderly. Automobile safety h" been studied extensively and has involved research on the elderly driver. There are some 12 million to 15 mil- lion licensed drivers over age 65 an increase of 25 percent in the I=t 10 years, with the sharpest rise among drivers over 69, up 68 percent (National Research Council, 1988~. There is some bin against the older driver as a safety hazard, but data supporting this attitude can be challenged (Jones and Pecl`, 1985~. A number of studies have attempted to relate vision and other functional capabilities of the older driver to their accident characteristics. However, the strength and consistency of this relationship, except in extreme cases, has not been sufficient for use In making licensing Sections. Attempts to

HUA~4N FACTORS PROBLEMS ASSOCIlAT~ WITH AGING 53 extend the accident/functional capability relationships to human fac- tors design criteria for the driving environment (roadways, markings, signs, give sources, lighting, intersections, controls, dashboards, and restraints) have been limited. ~ heavy traffic areas the danger of walking may rival that of driving. In general, pedestrian accidents intone the very young, the inexperienced, the old, the physically disabled, and the intoxicated (W~ler, 19783. The very young ~d the old tover 70) (Todd Ed Walker 1980) are the major victims and suffer most of the fatalities. The principal danger is In cro - mg traffic. The best means of achiev- ing pedestrian safety would be physical separation of vehicular and pedestrian traffic; however, short of thm, temporal measure separate tion and better design features of the crowing space would constitute substantial ~mpro~remente. Better design of signal lights and crossing points (e.g., curbs, signs, crossing make, and dimensions) are exam- pies of such unpro~rements. The potential impact of environmental design ~ shown by the observed decrease In pedestrian accidents associated with zebra-striped crossings and diagonal parking. Security Environment for Older Abuts Anecdotal and survey data suggest that there are three major areas of security concern for the elderly, their families and the larger community. These are (~) emergency access to fire, police, and health assistance; (2) security from the fear and victimization of crune; ~d (3) wanting and assistance In the case of natural disasters. Particularly vulnerable are the elderly living alone and those with a significant dmability. The latter represents about half of all persom over 65. Kelens and Griffithe (1983) reviewed evidence that suggests security ~ directly linked to the older person's mental and physical health. Security systen~ using new technology to provide access to emer- gency services are in use particularly among the elderly. These new Reprices include personad emergency alarms; remote monitoring gym terns for marital signs; and small tracking devices to detect wandering, a special problem of the Alzhe~mer'~ patient. Human factors has an important role in the development and dissemination of such technology. Crone and the fear of crime are topics of growing attention in social gerontology. While victimization of the elderly occurs less frequently than is the case for younger people, fear of crime may

54 HUAfAN FACTORS RIESEIARC~ NEWS FOR AN AGING POPULATION well be greater among the elderly (Yin, 1985). Especially vulnerable is the older woman living alone ~ art urban apartment or public housing who depends on public transportation (AIson, 1986~. While this aspect of security ~ predominately one of socis! and community policy, there is ample support ~ the literature for the fact that environmental design (lighting, high-rme apartmente) and security (surveillance policy) reduce crime. New technology ~ being applied to this Rue that wiD require human factors interface design and user-accept~ce studies. A trend ~ the field of dmaster reteach hen been to focus on subgroups with different degrees of vuInerabilit~r and limited ability to cope with emergency situations mclud~g the elderly (Tierney, Petak, and Hahn, 1987; Kilijanek and Drabek, 1979~. Research has been primarily concerned with sociological and postdisaster events, such as the ability to cope with the lom suffered. Other research has studied the behavior of the disabled and the elderly ~ hospi- tals, nursing homes, and residential care facilities after fires (Archea, 1979~. However, the focus of research has prmcipaDy been on rescue rather than on self-help and environmental design. General Ismes in Hem In Factors lleseard~ Related to Safety and Security and Aging A sizable body of literature has focused attention on the unpor- tance of safety Rues for the older person and clearly demonstrates the potential role that human factors might play in the design of safer environments. However, the same information base reveals a large gap between the empirical data available and the data needed for human factors applications. There is sufficient epidemiological detail on accidents and on un- safe and insecure environments of the older population upon which to base reteach prionties, hypotheses, and design activities. In addition, data do exist (e.g., from the National Center for Health Statistic, the National Accident Sampling System, state agencies, and the open literature), but none of these sources provide sufficiently detailed information on person and task characteristics, environmen- tal features and demands, ~d product features. Research yielding substantial epidem~ological detail will be necessary to direct and just tify hypotheses generation or human factors design (Miller, Recht, and Green, 1969; Planek, 1982; National Research Council, 1985a). A prerequisite for human factors design activity is information

H~4N FACTORS PROBLEMS ASSOCLAT}ED WITH AGING 55

56 HUMAN FACTORS RESEARCH NEEDS FOR AN AGING POPULATION medicine, gerontology, architecture, safety, and eIlgineer~g. Relax tively little research ~ this area can be clearly identified with the field of human factors. A search of the lot 30 years of the Journal of Human Factors produced only 17 articles specifically related to aging, only a few of which dealt directly with issues of safety; none that focused on security were found. Considering the effectiveness of environmental design in accident prevention (Robertson, 1975; Reilly, Kurke, ~d Bukenma~er, 1980) relative to the effectiveness of tragic laws or Denver training (Lund and Williams, 1984; McKnight, Simone, and Weidman, 1982), Tuitional research in this area would seem warranted. LEISURE ACTIVITIES The topic of leisure is closely related to the topics of work and retirement. This ~ because adult leisure activity ~ primarily con- centrated in the retirement period. Given the increasing longevity of persons reaching age 65 and the declining employment rate among older people, the number of potential years of leisure activity is grow- ing. This creates a need to ensure that the po~tretirement leisure years are satisfying and meaningful. A common problem associated with aging is adjustment to the substitution of leisure for work (Myers, Manton, and Bacellar, l986~. Several investigators (e.g., Gordon, Gaits, and Scott, 1976) have shows that older people find leisure less satisfying than work and that, for those older persons who do seek out leisure activities, recre- ation programs have not kept pace with their demands in quality or quantity. Because future generations of older adults will be healthier, better educated, az,6 more affluent (Burru~Barnrnel and Bammel, 1985), it will be essential to provide meaningful and varied leisure ser- vices. In order for human factors specialists to make contributions in this area, basic information is needed regarding current leisure patterns of older people. Such knowledge will permit identification Of ways in which human factors efforts can improve lemure options for older people (Kahne, 1987~. Current information about aging and leisure is limited. This is partially due to lack of consensus regarding the definition of the term ~lemure.~ Although the common definition of leisure has been "nonwork-related activities," more recently, Unobligated or ~dis- cretionary" time have been proposed. These differences in the oper- ational definitions of the term make it difficult to draw conclusions

lIUMAN FACTORS PROBLEMS ASSOCIATED WITH AGING 57 from inventory stuclies of adult lemure behavior. Although these did ferences are noted in reports on the most popular activities among the elderly, which seem to include TV viewing, visiting friends, write ing letters, and dowg jobs at home, the majority of lemure activities take place within the home and are m~ividual pursuits (Moss and Lawton, 1982~. It is known that engagement in physical activities declines with age, and this decline is especially significant for women. Data suggest that 60 percent of people over 60 are physically unfit (Bu~Tu~B=nmel and Bal}unel, 1985~. This is an important finding since lack of physical activity accelerates the onset and progression of many ages related deficits and diseases. Possible human factors research in this area might include finding ways to increase the participation of older adults in physical activities. This might involve, for example, redesign of sports athletic equipment or identifying which types of activities are most suitable for older people in terms of activity demands and adult capabilities. As IsmAhola (1980) points out, it is important for older adults to be able to make alterations or substitutions within activities so that they can continue to enjoy a broad leisure repertoire. This goal can be realized by changing the intensity of participation within an activity, by altering the focus of participation, or by adopting new forms of leisure pursuits. Such results are predicated on an under- st8Dding of what types of problems older people encounter when attempting leisure pursuits and identifying strategies to circumvent those problems. Currently, there are only limited data regarding the reasons older people choose to participate in one type of leisure activity as opposed to another ~d what types of obstacles they encounter. McAvoy (1979) conducted a surrey of people aged 65 years and over and found that lack of ability was the most important problem cited as preventing participation in preferred activities. This suggests that the demands of many leisure pursuits pore obstacles for older adults and that activities need to be structured to lemen demands or activities need to be identified that are equally satefying but less demanding. Lack of companionship, restricted mcome, and problems with transportation are also mentioned in the literature as being ~ignifi- cant obstacles to participation in leisure activities. This suggests a need to identify ways in which leisure activities can be made more readily available to persons in older age groups. At.

58 GUAM FACTOR ITCH IS FOR ~ AGOG POPUM"ON ~ 8u~y, the forgoing human factors reteach is warranted within the area of leisure "d recreation: (1) data regarding current leisure patterns of older adults, including types of activities pursued, frequency of participation in activities, and reams for choice of activities; (2) task-analytic information identifying specific types of problems older adults encounter when sttempt~g to engage ~ recross ational activities; and (3) identification of strategies to modify the time and location structure of activities, equipment, or requirements of lemure events so that they are more accemible to older adults.

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This book describes the demographic, sociological, and ecological background of the aging society, identifies human factors problems associated with aging, summarizes currently relevant information, and recommends directions for research. It suggests a program of research and technology development for the purpose of ameliorating the effects of functional changes that accompany the aging process and provides a basis for additional research and application of human factors engineering data to the design of environments in which aging people must function.

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