Frailty Index as a Risk Stratification Tool for the Proposed CMS Surgical Hip and Femur Fracture Treatment Bundle.

Abstract

To determine the extent to which the Comprehensive Geriatric Assessment based Frailty Index (FI) predicts in-hospital costs of care for older adult hip fracture patients with implications for risk adjustment of future bundled payment models by identifying higher-cost patients. Retrospective cohort study. One academic level 1 trauma center in the United States of America. Included were all patients over the age of 65 who underwent surgery for a femoral neck or intertrochanteric hip fracture (OTA/AO 31A and 31B) between March 2018 and August 2020 and had a frailty index recorded for the injury admission. The primary outcome of interest was a percentage difference of in-hospital total cost of care between severely frail, moderately frail, and non-frail patients. Univariate and multivariate regression were also used to evaluate the association of frailty index, along with other demographic and clinical variables, with cost of care. A total of 326 patients were included. Compared to non-frail patients, the average in-hospital cost was 20% higher for severely frail patients and 12% higher for moderately frail patients (both p<0.05). In univariate regression, FI was found to have a significant association with total cost (β=$1,106 incremental cost per 0.1 increase in FI, p=0.005) and direct cost (β=$586 incremental cost per 0.1 increase in FI, p=0.014). Higher Frailty Index scores are associated with increased costs of in-hospital treatment for hip and femur fractures as both a categorical and continuous variable. Thus, Frailty Index offers a potential risk adjustment tool for future hip and femur fracture payment bundles. III.