Frailty and chronic diseases in older adults.

There are two hallmarks of aging that must be considered primary concerns when trying to improve health for older adults: frailty and chronic diseases. Some pathologic mechanisms related to diseases may help to explain frailty. This article describes known associations among frailty and chronic diseases and introduces punished inefficiency as an explanatory framework for frailty. Punished inefficiency proposes that having several physiologic impairments leads to physiologic inefficiencies. These inefficiencies may become manifest as frailty, often in the presence of disease. Therefore, frail older adults perform less external work because they must spend more on an absolute scale out of a smaller pool of internal resources. Stress imposed on frail older adults strengthens this negative feedback to activity, leading to disuse. This article discusses how people with frailty and chronic diseases may experience a malignant course and thereby intends to improve the ability to identify beneficial biologic and health care delivery strategies for older adults with, or at risk of, frailty.