Operationalizing a Frailty Index from a Standardized Comprehensive Geriatric Assessment

Abstract

OBJECTIVES: To construct and validate a frailty index (FI) that is clinically sensible and practical for geriatricians by basing it on a routinely used comprehensive geriatric assessment (CGA) instrument. DESIGN: Secondary analysis of a 3-month randomized, controlled trial of a specialized mobile geriatric assessment team. SETTING: Rural Nova Scotia. Participants were seen in their homes. PARTICIPANTS: Frail older adults, of whom 92 were in the intervention group and 77 in the control group. MEASUREMENTS: A standard CGA form that accounts for impairment, disability, and comorbidity burden was scored and summed as a frailty index (FI-CGA). The FI- GCA was stratified to describe three levels of frailty. Pa- tients were followed for up to 12 months to determine how well the index predicted adverse outcomes (institutionali- zation or mortality, whichever came first). RESULTS: The three levels of frailty were mild (FI-CGA 0-7), moderate (FI-CGA 7-13), and severe (FI-CGA>13). Demographic and social traits were similar across groups, but greater frailty was associated with worse function (r 50.55) and mental status (r 50.33). Those with moder- ate and severe frailty had a greater risk of adverse outcomes than those with mild frailty (unadjusted hazard ratio 51.9 and 5.5, respectively). There was no difference between frailty groups in mean 3-month goal-attainment scaling scores. Intrarater reliability was 0.95. CONCLUSION: The FI-CGA is a valid, reliable, and sen- sible clinical measure of frailty that permits risk stratifica- tion of future adverse outcomes.J Am Geriatr Soc 52:1929- 1933, 2004.