Public health significance of the frailty index

Abstract

Background. A quantifiable indicator of frailty would be very useful in assessing the health state of older populations, as well as enable the effect of interventions to be evaluated over time. Methods. A total of 2032 people aged 70 years and over recruited by stratified random sampling, and information obtained regarding physical and functional health, and psychological factors. The frailty index (FI) was constructed from 62 variables. Associations between the FI, and changes in ADL score, mental score, and hospitalization days over a 10-year period were evaluated. Results. For the baseline to 3-year changes, a 0.10 increase in baseline FI is accompanied by a 0.499-point faster drop in ADL score, a 0.223-point faster decline in mental score, and 4.57-day faster increase in hospital days. For 3 – 10-year changes, frailty was a significant predictor only of changes in mental score, with results indicating that, on average, each increase of 0.10 in the baseline frailty index was associated with 0.613-point drop in mental score during this period. Chronological age and frailty had differential associations with those changes. Conclusion. The FI is a valid indicator of morbidity and requirement for health and social services for ageing populations.