Identifying common characteristics of frailty across seven scales.

Objectives: To determine whether commonly used frailty scales exhibit shared characteristics when applied to a representative sample of middle-aged and older Europeans.

Design: Secondary analysis of the Survey of Health, Ageing, and Retirement in Europe (SHARE).

Setting: Eleven European countries.

Comparison of alternate scoring of variables on the performance of the frailty index.

Background: The frailty index (FI) is used to measure the health status of ageing individuals. An FI is constructed as the proportion of deficits present in an individual out of the total number of age-related health variables considered. The purpose of this study was to systematically assess whether dichotomizing deficits included in an FI affects the information value of the whole index.