chronic diseases. For example, much can be done to reduce the risk of disabling conditions for people with diabetes, but as the box entitled Preventing Diabetes-Related Disability explains, the disease persists as one of the leading causes of disabling conditions.
Thus, although much is known about the prevention of certain chronic diseases and associated disabling conditions, sometimes the preventive and rehabilitative interventions that are used are not underlain by sufficient understanding, and their effectiveness has not been thoroughly evaluated. Moreover, prevention efforts are hampered by limited understanding of the natural histories of many chronic diseases, of the aging process, and of the relationships among chronic disease, aging, and functional outcomes. Thus it must be recognized that our knowledge has limits and that we often fail to translate existing knowledge into practice.
The limitations of care delivery systems must also be recognized. The needs of people with long-term conditions mesh poorly with a health care system that is oriented toward the treatment of acute conditions, where care is akin to crisis management. People with chronic conditions require continuity of care and their needs are diverse, encompassing more than medical treatment. If, for example, social support is lacking, a person's well-being may deteriorate despite the availability of adequate health care. Unfortunately, systems for the delivery of social services are fragmented and fail to achieve the continuity that people with chronic conditions often require.
The remainder of this section describes an approach for conceptualizing disability prevention during the life course among people with chronic disease, summarizes some opportunities for prevention, and discusses shortcomings in current systems for the delivery of health care and social services. Much of the discussion focuses on the prevention and management of chronic disease in the elderly.
Unlike acute conditions and injuries, chronic diseases often do not have an identifiable point of onset, and they frequently entail gradually progressive declines in functional capacity. In terms of the committee's model of the disabling process (see Chapter 3), people with chronic diseases are usually first identified when their condition is at the impairment stage (i.e., with a loss or abnormality of physiological, psychological, or anatomical structure or function).
People with chronic disease are at increased risk of functional limitation and disability, and, absent effective preventive measures, the quality of their lives is also likely to decline. In the minds of many—layman and professional alike—the aging processes during the later stages of adulthood are virtually synonymous with chronic disease, and prospects for improvement