Claims-based frailty index (CFI) estimates a deficit-accumulation frailty index using International Classification of Diseases (ICD) diagnosis codes, Current Procedural Terminology (CPT) codes, and Healthcare Common Procedure Coding System (HCPCS) codes in the prior 12 months in administrative claims data.

Please refer to "Research Background - Claims-Based Frailty Index" file within each sub-dataverse for interpretation, validation data against clinical measures and health outcomes, and annotated references. Refer to "Frailty Index Code Guide" file to implement CFI algorithms in different statistical softwares and programming languages.

The original SAS program was developed and validated by Dr. Kim and his team at the Brigham and Women's Hospital Division of Pharmacoepidemiology and Pharmacoeconomics, supported by National Institute on Aging (grants K08 AG051187 and R01 AG062713). Programs in Stata, R, Python, and Java were developed by Westat and VillageMD and are based on the original SAS program.