Hospital competition and financial performance: the effects of ambulatory surgery centers.

Ambulatory surgery centers (ASCs), limited-service alternatives for treating surgery patients not requiring an overnight stay, are a health-care service innovation that has proliferated in the U.S. and other countries in recent years. This paper examines the effects of ASC competition on revenues, costs, and profit margins of hospitals that also provided these services as a subset of their general services in Arizona, California, and Texas during the period 1997-2004. We identified all ASCs operating during the period in the 49 Dartmouth Hospital Referral Regions in the three states. The results of fixed effects models suggested that ASCs are meaningful competitors to general hospitals. We found downward pressure on revenues, costs, and profits in general hospitals associated with ASC presence.