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

• Published in: The journals of gerontology. Series A, Biological sciences and medical sciences Biological sciences and medical sciences, 2021-07, Vol.76 (7), p.1318-1325
• Main Authors: Cheng, David, DuMontier, Clark, Yildirim, Cenk, Charest, Brian, Hawley, Chelsea E, Zhuo, Min, Paik, Julie M, Yaksic, Enzo, Gaziano, J Michael, Do, Nhan, Brophy, Mary, Cho, Kelly, Kim, Dae H, Driver, Jane A, Fillmore, Nathanael R, Orkaby, Ariela R
• Format: Article
• Language: English
• Subjects: Aged; Classification; Electronic health records; Electronic medical records; Frailty; Frailty - classification; Humans; International Classification of Diseases; Male; Mortality; THE JOURNAL OF GERONTOLOGY: Medical Sciences; United States; United States Department of Veterans Affairs; Veterans; Veterans - classification
• ISSN: 1079-5006; 1758-535X; 1758-535X
• DOI: 10.1093/gerona/glab071

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.