Longitudinal changes in a claims-based frailty proxy measure compared to concurrent changes in the Fried frailty phenotype.

Abstract

Frailty is a dynamic aging-related syndrome, but measuring frailty transitions is challenging. The Faurot frailty index is a validated Medicare claims-based frailty proxy based on demographic and billing information. We evaluated whether three-year changes in the Faurot frailty index were consistent with concurrent changes in the frailty phenotype in a cohort of older adults. We used longitudinal data from the National Health and Aging Trends (NHATS) study with Medicare claims linkage (2010-2018). We identified older adults (66+ years) in the 2011 and 2015 NHATS cohorts with at least one year of Medicare fee-for-service continuous enrollment (N=6,951). We described annual changes in mean claims-based frailty for up to three-years, based on concurrent transitions in the frailty phenotype. At baseline, 32% were robust, 48% prefrail, and 19% frail based on the frailty phenotype. Mean claims-based frailty for older adults who were robust at baseline and worsened to frail increased over three-years (0.09-0.25). Similarly, those who worsened from prefrail to frail experienced an increase in mean claims-based frailty (0.14-0.26). Improvements in the frailty phenotype did not correspond to decreases in claims-based frailty. Older adults whose frailty phenotype improved over time had a lower baseline claims-based frailty score than those who experienced stable or worsening frailty. Older adults who experienced a frailty phenotype worsening over three years experienced concurrent increases in the Faurot frailty index. Our results suggest that claims data may be used to identify clinically meaningful worsening in frailty.