Frailty Assessment Approaches

Definition and Classification

The Frailty Phenotype (Fried Model) conceptualizes frailty as a physical syndrome defined by five specific criteria: low grip strength, slow walking speed, unintentional weight loss, reduced usual activities, and self-reported exhaustion, with frailty diagnosed when three or more of these five features are present 1
The Frailty Index based on deficit accumulation views frailty as a general age-related state of poor health proportional to accumulated health deficits, with the degree of frailty expressed as the fraction of deficits present relative to the total number considered 1

The FRAIL Scale is a popular self-report variant that adds comorbidity assessment to the phenotype approach, and the Clinical Frailty Scale (CFS) proposes ordered combinations of high-information deficits to grade frailty severity on a 1-9 scale 1, 2
Modified frailty indices using fewer items have been criticized as too brief to constitute true deficit accumulation indices, and when at least 30 age-related items are considered in a frailty index, the degree of frailty does not depend strongly on which specific items are counted 1

Both the phenotype and deficit accumulation approaches consistently classify people at increased risk of death at the group level, reduce the explanatory power of age alone, and appear to share genetic determinants 1
For older adults with cognitive impairment due to dementia, expert consensus recommends using brief, straightforward tools accessible to various clinicians 3, 4