ABSTRACT
There is a progressive increase in morbidity and mortality rates associated with a given medical condition in older people. For example, the mortality rate during hospitalization for myocardial infarction in patients older than age 80 is ten times higher than the rate for middle-aged people (Maggioni et al., 1993). Such increased risks may be due to the presence of multiple coexisting medical problems as well as a decrease in homeostatic reserve capacity of multiple key regulatory systems. For example, the age-related decline in renal function may not cause any problem for an older adult until the individual becomes acutely ill with a life-threatening illness such as acute myocardial infarction with its associated risk of kidney injury due to impaired blood flow. On the other hand, higher risks associated with illness in an older adult provide an opportunity for effective intervention. Indeed, medical or surgical interventions often show greater benefit in an older, higher risk population. For example, the number of lives saved per 1,000 people treated with thrombolytic therapy for acute myocardial infarction is greater in an older age population (Topol & Califf, 1992), and the number of strokes prevented per given number of people treated for hypertension is greater in older people (Insua et al., 1994). However, such benefits of treatment occur in a setting in which the risks of treatment are also greater, such as bleeding complications from thrombolytic therapy (Gurwitz, Avorn, Rose-Degnan, Choodnovskiy, & Ansell, 1992) or orthostatic hypotension from use of antihypertensive drugs.
