Indicators of Function in the Geriatric Population

A ssessment of function of an elderly person can be conducted at a number of different levels and using methods which span a wide range of sophistication. On a clinical level, assessment of overall functional capability is a central theme of the field of geriatric medicine. However, with rapid advances in technology, assessment of function of individual organs or organ systems, of individual cells, and even of specific molecules will become increasingly feasible, even in the context of a household survey or evaluation. This chapter will review aspects of function at each of these levels in humans, the various types of total organism functions that are usually assessed clinically and can predict outcomes, and issues related to choice of measures of function for this population. Measurement of function at any of these levels may define the presence of a disease state. For example, a diagnosis of congestive heart failure or renal failure is based on a certain level of functional impairment of the heart or kidneys. However, most diseases are characterized either by overt pathology like tissue damage (e.g., myocardial infarction), inflammation (e.g., infection), or invasion (e.g., cancer); the presence of defined clinical characteristics in a patient (e.g., depression or malnutrition); or a laboratory measurement which predicts subsequent pathology (e.g., high blood pressure or high cholesterol level).