Comparing the mix of patients in various outpatient surgery settings.

Medicare's facility payment rates for an ambulatory surgical procedure differ among settings. These differences raise questions about how Medicare should pay for the same procedure in various settings. In exploring this issue, it is important to look at whether the type of patients treated varies by setting. The recent growth in specialty facilities offers another reason to analyze the mix of patients. This study compares the medical complexity of Medicare beneficiaries treated in ambulatory surgical centers (ASCs) and outpatient departments. Outpatient departments treat beneficiaries who are more medically complex, so ASCs might incur lower costs when providing similar procedures.