Linking the National Cardiovascular Data Registry CathPCI Registry With Medicare Claims Data Validation of a Longitudinal Cohort of Elderly Patients Undergoing Cardiac Catheterization

Background—The National Cardiovascular Data Registry CathPCI Registry was recently linked with longitudinal Centers for Medicare & Medicaid (CMS) claims data. The degree to which this linked cohort is representative of the overall CathPCI Registry and CMS PCI populations is unknown. Methods and Results—CathPCI Registry records were linked to CMS inpatient claims using indirect identifiers. We examined the degree to which hospitals and patients in the linked cohort are representative of the elderly (≥65 years) CathPCI Registry and CMS populations. From 2004 to 2006, 1492 hospitals filed CMS PCI claims and 663 contributed CathPCI Registry data. Of these hospitals, 643 (97%) were linked across data sources. Compared with all CMS PCI hospitals, the linked data set contained fewer governmental, northeastern, southern, and low-volume (<200 beds) sites. Among CMS beneficiaries, 993 351 PCI procedures were performed, including 398 508 (40.1%) at centers in the linked database. Of these, 341 916 (86%) were linked ...