Medicare Claims Data Resources: A Primer for Policy-Focused Radiology Health Services Researchers

As societal stakeholders call for increased evidence-based health policy, considerable attention has focused on Medicare, the country's largest payer. Concurrently, medical imaging has come under considerable scrutiny as a contributor to rising health care expenditures. Accordingly, many recent studies have focused on multiple factors related to the utilization of imaging among Medicare beneficiaries. This article summarizes several national Medicare fee-for-service data sources relevant to supporting ongoing investigations. Aggregated 100% data sets include the Physician/Supplier Procedure Summary Master Files and the Medicare Provider Utilization and Payment Data: Physician and Other Supplier Public Use File. The former focuses on services, specialties, and sites of service; the latter focuses on providers. Both permit high-level national assessments of imaging utilization and spending. Individual 5% random-sample claims-level data sources include the Carrier Standard Analytical File Limited Data Set and the Research Identifiable File, which contain greater beneficiary-level information. Both facilitate more robust patient- and encounter-level analyses and some assessment of downstream outcomes but involve greater costs and require greater privacy oversight. More recently, Medicare data are being merged with registry data (eg, Surveillance, Epidemiology, and End Results-Medicare Linked Database files), creating opportunities for even more robust analyses given richer clinical information. Understanding these data sets and trade-offs in their use will aid policy-focused imaging health services researchers in most effectively conducting their investigations.