Changing Abdominal Imaging Utilization Patterns: Perspectives From Medicare Beneficiaries Over Two Decades.

PURPOSE: To assess changing utilization patterns of abdominal imaging in the Medicare fee-for-service population over the past two decades.

METHODS: Medicare Physician Supplier Procedure Summary master files from 1994 through 2012 were used to study changes in the frequency and utilization rates (per 1,000 Medicare beneficiaries per year) of abdominal CT, MRI, ultrasound, and radiography.

RESULTS: In Medicare beneficiaries, the most frequently performed abdominal imaging modality changed from radiography in 1994 (207.4 per 1,000 beneficiaries) to CT in 2012 (169.0 per 1,000). Utilization rates of abdominal MR (1037.5%), CT (197.0%), and ultrasound (38.0%) all increased from 1994-2012 (but declined briefly from 2007 to 2009). A dramatic 20-year utilization rate decline occurred for gastrointestinal fluoroscopic examinations (-91.9% barium enema, -80.0% upper gastrointestinal series) and urologic radiographic examinations (-95.3%). Radiologists were the dominant providers of all modalities, accounting for >90% of CT and MR studies, and >75% of most ultrasound examination types.

CONCLUSIONS: Medicare utilization of abdominal imaging has markedly changed over the past two decades, with overall dramatic increases in CT and MRI and dramatic decreases in gastrointestinal fluoroscopic and urologic radiographic imaging. Despite these changes, radiologists remain the dominant providers in all abdominal imaging modalities.