In general, people with activity limitations are substantially older and poorer than those without limitations. With regard to age, 32 percent of people with activity limitation are over 65, compared with 9 percent of people without limitations. Only 10 percent of the population with activity limitations are under 18, compared with 29 percent of people without limitation. Furthermore, 22 percent of the population with activity limitations—compared with 10 percent of people without limitation—have incomes under $10,000, and 18 percent—compared with 33 percent—have incomes over $35,000.
The NHIS data (National Center for Health Statistics, 1989a) also provide perspectives on aspects of disability beyond activity limitation. For instance, respondents were restricted in activity for an average of 14.7 days in 1988 because of acute and chronic conditions, including an average of 6.3 bed-disability days. Furthermore, 39.1 percent of the respondents rated their own health as "excellent," 27.8 percent as "very good," and 23.2 percent as "good." Only 9.9 percent rated their health as "fair" or ''poor." This is smaller than the proportion—13.7 percent—that experience any activity limitation. As with activity limitation, the proportion of people who rate their health as fair or poor increases with age, decreases with income, and is higher for blacks than for whites.
As discussed below, a variety of other surveys and data systems generate estimates of the prevalence of disability. Tables 2-1, 2-2, and 2-3 present some of the measures available from the NHIS and other sources. The target population is usually the civilian noninstitutionalized population, but each study uses different criteria for identifying "disability." Without exception, however, people with disabilities tend to be older, to have less education, and to be poorer than the general population.
The ICD survey led to an estimate that about 27 million people, 15 percent of the population age 16 and over, had some disability. Broken down by age in Table 2-1, the prevalence rates are similar to those from the NHIS for the population under age 65. For people 65 and over, however, the NHIS rate is about a third higher. Even though the ICD criteria for disability could be expected to include more people than the NHIS, use of only telephone interviews may have tended to exclude older people with disabilities.
Among those included in the ICD survey, 8 percent reported that they experienced no limitation in their activities, and 50 percent did not consider themselves disabled even though they met at least one of the survey's "disability" criteria. However, 46 percent said that they were prevented completely from working, going to school, or keeping house. Two-thirds of the people under age 65 were not working, and two-thirds of the people who were not working reported wanting to work.