Ability of Medicare Claims Data to Identify Nursing Home Patients A Validation Study

Background: There are currently no Medicare claims-based algorithms to identify patients receiving nursing home care (NHC). This constitutes an important limitation in outcome studies Using population-based data. Objectives: To assess the ability of claims data to identify patients receiving NHC, using file nursing home Minimum Data Set (MDS) as the gold standard. We hypothesized that physician claims carrying, relevant Evaluation and Management (E&M) procedure codes would be an adequate Source to identify nursing home patients. Research Design: Cross-sectional Study using the Ohio Cancer-Aging Linked Database, developed by linking records from the Ohio Cancer Incidence Surveillance System with multiple Sources of data, including Medicare enrollment and claims files, and the MDS. Subjects: Patients 65 years of age or older residing. in Ohio, and diagnosed with incident breast, prostate, or colorectal cancer during years 1997-2001. We limited our study cohort to fee-for-service patients receiving NHC during calendar year 2002, with a look-back period in the claims data to November 2001. Measures: Sensitivity and positive predictive value (PPV). Results: Sensitivity, or the proportion of patients identified through file MDS file who were also successfully identified through the claims data was 88.1%. PPV. or the proportion of patients with the relevant E&M codes who were also identified in the MDS file was 83.9%. Conclusions: Carrier files may be an acceptable data Source 10 identify nursing home patients, paving the way for future risk adjustment techniques to account for nursing home status.