Medicare services provided by cardiologists in the United States: 1999-2008.

BACKGROUND Services provided by cardiologists represent a major portion of Medicare expenditures for specialist physicians. The absolute growth and distribution of these services over the past decade have not been well described. METHODS AND RESULTS We analyzed fee-for-service Medicare Part B claims for each year from 1999-2008 and selected claims from physicians whose specialty code was cardiology. We then grouped approximately 1000 CPT-9 codes into 45 specific service groups that were then further aggregated into 3 broad service categories: evaluation and management, noninvasive procedures, and invasive procedures. Our main outcome measures were services and allowed charges per 1000 beneficiaries. Sample size ranged from 30.9 million beneficiaries in 1999 to 31.7 million in 2008. During this 10-year period, the number of claims from cardiologists increased 44% (from 2082-2997 per 1000 beneficiaries) while the allowed charges increased 28% after adjusting for inflation (in 2008 dollars, from $181,397-231,728 per 1000 beneficiaries). Evaluation and management services and invasive procedures contributed relatively little to this growth. Instead, most of the growth involved noninvasive procedures--with a 70% increase in claims. Although the most dramatic increases in noninvasive procedures involved emerging imaging technologies (cardiac CT, MRI, and PET scanning), the bulk of the growth occurred in two established technologies: resting echocardiograms and stress tests with nuclear imaging. CONCLUSIONS Most of the growth in services provided by cardiologists over the past decade is the result of increased noninvasive imaging.