Use of physicians' services under Medicare's resource-based payments

BACKGROUND: In 1992, Medicare implemented the resource-based relative-value scale, which established payments for physicians' services based on relative costs. We conducted a study to determine how the use of physicians' services changed during the first decade after the implementation of this scale. METHODS: With the resource-based relative-value scale, Medicare payments are based on the number of relative-value units (RVUs) assigned to physicians' services. The total number of RVUs reflects the volume of physicians' work (the time, skill, and training required for a physician to provide the service), practice expenses, and professional-liability insurance. Using national data from Medicare on physicians' services and American Medical Association files on RVUs, we analyzed the growth in RVUs per Medicare beneficiary from 1992 to 2002 according to the type of service and specialty. We also examined this growth with respect to the quantity and mix of services, revisions in the valuation of RVUs, and new service codes. RESULTS: Between 1992 and 2002, the volume of physicians' work per Medicare beneficiary grew by 50%, and the total RVUs per Medicare beneficiary grew by 45%. The quantity and mix of services were the largest sources of growth, increasing by 19% for RVUs for physicians' work and by 22% for total RVUs. Our findings varied among services and specialties. Revised valuation of RVUs was a key source of the growth in RVUs for physicians' work and total RVUs for evaluation and management and for tests. New service codes were the largest drivers of growth for major procedures (accounting for 36% of the growth in RVUs for physicians' work and 35% of the growth in total RVUs), and the quantity and mix of existing services were the largest drivers of growth for imaging. The growth in RVUs for physicians' work was greatest in cardiology (114%) and gastroenterology (72%). The total growth in RVUs was greatest in cardiology (99%) and dermatology (105%). CONCLUSIONS: In the first 10 years after the implementation of the resource-based relative-value scale, RVUs per Medicare beneficiary grew substantially. The leading sources of growth varied among service types and specialties. An understanding of these sources of growth can inform policies to control Medicare spending.