Relative Fitness and Frailty of Elderly Men and Women in Developed Countries and Their Relationship with Mortality

Objectives: To investigate the relationship between accumulated health‐related problems (deficits), which define a frailty index in older adults, and mortality in population‐based and clinical/institutional‐based samples. Design: Cross‐sectional and cohort studies. Setting: Seven population‐based and four clinical/institutional surveys in four developed countries. Participants: Thirty‐six thousand four hundred twenty‐four people (58.5% women) aged 65 and older. Measurements: A frailty index was constructed as a proportion of all potential deficits (symptoms, signs, laboratory abnormalities, disabilities) expressed in a given individual. Relative frailty is defined as a proportion of deficits greater than average for age. Measures of deficits differed across the countries but included common elements. Results: In each country, community‐dwelling elderly people accumulated deficits at about 3% per year. By contrast, people from clinical/institutional samples showed no relationship between frailty and age. Relative fitness/frailty in both sexes was highly correlated (correlation coefficient >0.95, P