Identification of Heart Failure Events in Medicare Claims: The Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: We examined the accuracy of Medicare heart failure (HF) diagnostic codes in the identification of acute decompensated (ADHF and chronic stable (CSHF) HF. METHODS AND
RESULTS: Hospitalizations were identified from medical discharge records for Atherosclerosis Risk in Communities (ARIC) study participants with linked Medicare Provider Analysis and Review (MedPAR) files for the years 2005-2009. The ARIC study classification of ADHF and CSHF, based on adjudicated review of medical records, was considered to be the criterion standard. A total 8,239 ARIC medical records and MedPAR records meeting fee-for-service (FFS) criteria matched on unique participant ID and date of discharge (68.5% match). Agreement between HF diagnostic codes from the 2 data sources found in the matched records for codes in any position (κ > 0.9) was attenuated for primary diagnostic codes (κ < 0.8). Sensitivity of HF diagnostic codes found in Medicare claims in the identification of ADHF and CSHF was low, especially for the primary diagnostic codes.
CONCLUSION: Matching of hospitalizations from Medicare claims with those obtained from abstracted medical records is incomplete, even for hospitalizations meeting FFS criteria. Within matched records, HF diagnostic codes from Medicare show excellent agreement with HF diagnostic codes obtained from medical record abstraction. The Medicare data may, however, overestimate the occurrence of hospitalized ADHF or CSHF.