Figure 1. Two Approaches to Identifying Frailty.

In this figure we describe two leading theories of frailty: the physical phenotype or phenotypic frailty and the cumulative deficit frailty. The phenotypic frailty uses five direct measurements of physical characteristic: weight loss, energy level, physical activity, walking speed, and muscle strength. The cumulative deficit approach measures health-related deficits in a broad range of systems including morbidity, physical function, nutrition, cognition, mental health, and geriatric syndromes.