Nathanael R. Fillmore
Publications / 2021
paper
Journals of Gerontology: Series A2021doi:10.1093/gerona/glab071

Updating and Validating the U.S. Veterans Affairs Frailty Index: Transitioning From ICD-9 to ICD-10.

David Cheng†, Clark DuMontier†, Cenk Yildirim, Brian Charest, Chelsea E. Hawley, Min Zhuo, Julie M. Paik, Enzo Yaksic, J. Michael Gaziano, Nhan Do, Mary Brophy, Kelly Cho, Dae H. Kim, Jane A. Driver, Nathanael R. Fillmore‡, Ariela R. Orkaby‡

† Equal first authorship · ‡ Equal senior authorship

Summary

Researchers updated the Veterans Affairs Frailty Index by transitioning its diagnostic codes from ICD-9 to ICD-10 to ensure accurate frailty measurement in contemporary electronic health records. The updated index remains a stable and valid predictor of mortality, with frail patients experiencing more than twice the risk of death compared to nonfrail patients.

Key result

Patients classified as frail (VA-FI > 0.2) demonstrated a hazard of death more than 2 times higher than nonfrail patients (VA-FI ≤ 0.1).

Abstract

BACKGROUND: The Veterans Affairs Frailty Index (VA-FI) is an electronic frailty index developed to measure frailty using administrative claims and electronic health records data in Veterans. An update to ICD-10 coding is needed to enable contemporary measurement of frailty. METHOD: International Classification of Diseases, ninth revision (ICD-9) codes from the original VA-FI were mapped to ICD-10 first using the Centers for Medicaid and Medicare Services (CMS) General Equivalence Mappings. The resulting ICD-10 codes were reviewed by 2 geriatricians. Using a national cohort of Veterans aged 65 years and older, the prevalence of deficits contributing to the VA-FI and associations between the VA-FI and mortality over years 2012-2018 were examined. RESULTS: The updated VA-FI-10 includes 6422 codes representing 31 health deficits. Annual cohorts defined on October 1 of each year included 2 266 191 to 2 428 115 Veterans, for which the mean age was 76 years, 97%-98% were male, 78%-79% were White, and the mean VA-FI was 0.20-0.22. The VA-FI-10 deficits showed stability before and after the transition to ICD-10 in 2015, and maintained strong associations with mortality. Patients classified as frail (VA-FI > 0.2) consistently had a hazard of death more than 2 times higher than nonfrail patients (VA-FI ≤ 0.1). Distributions of frailty and associations with mortality varied with and without linkage to CMS data and with different assessment periods for capturing deficits. CONCLUSIONS: The updated VA-FI-10 maintains content validity, stability, and predictive validity for mortality in a contemporary cohort of Veterans aged 65 years and older, and may be applied to ICD-9 and ICD-10 claims data to measure frailty.