form ADLs and IADLs, one's dependency on others for care increases. As many as one to one-and-a-half million elderly individuals residing in the community or in institutions are unable to carry out five or more ADLs (Branch et al., 1984). However, recent studies indicate that such deficits are not static and may indeed respond to rehabilitation (Williams, 1988).
Within the general area of functional disability research, two general areas stand out: studies of health promotion and disease prevention in older persons and studies of specific geriatric syndromes.
The mechanisms and diseases that lead to age-related increases in disability have not been elucidated. With few exceptions, research in health promotion and disease prevention has not focused on older cohorts. Although substantial data on the relationship of traditional cardiovascular risk factors to the subsequent incidence of cardiovascular disease in older men and women are emerging from the aging Framingham cohorts, few data are available to indicate whether intervention in these risk factors affects subsequent rates of cardiovascular disease, including stroke, heart attacks, and congestive heart failure. Some limited data exist in the area of diastolic hypertension, and a major multicenter study is under way to evaluate the contributions of isolated elevations in systolic blood pressure to these end points, particularly stroke. However, few studies adequately address remediable risk factors for other important geriatric disorders, including osteoporosis, dementia, disability, and total mortality.
Too often, investigators have generalized findings from middleaged adults to older individuals without recognizing the major effects of the substantially altered physiologic substrates with advancing age. No a priori assumption can be made that risk factors for important diseases in middle age carry the same relative or the same attributable risk in old age. From a lifespan perspective, it is important to note that many prevention issues pertinent to older people should first be addressed to young adults (IOM, 1990a,b).
While a substantial number of specific research areas have been identified, two are particularly salient:
Research should be conducted on the interacting effects of age, lifestyle factors, and disease on the disability status of older persons.
Studies should be undertaken to determine the effectiveness of various disease prevention strategies or practices in older persons.