Medicare

Medicare pays for surgical procedures performed at ambulatory surgical centers (ASC) and hospital outpatient departments through different payment systems. Although they perform a similar set of procedures, no comparison of ASC and hospital outpatient per-procedure costs has been conducted. The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 directed GAO to compare the relative costs of procedures furnished in ASCs to the relative costs of those procedures furnished in hospital outpatient departments, in particular, how accurately the payment groups used in the hospital outpatient prospective payment system (OPPS) reflect the relative costs of procedures performed in ASCs. To do this, GAO collected data from ASCs through a survey. GAO also obtained hospital outpatient data from the Centers for Medicare & Medicaid Services (CMS).

GAO determined that the payment groups in the OPPS, known as ambulatory payment classification (APC) groups, accurately reflect the relative cost of procedures performed in ASCs. GAO calculated the ratio between each procedure's ASC median cost, as determined by GAO's survey, and the median cost of each procedure's corresponding APC group under the OPPS, referred to as the ASC-to-APC cost ratio. GAO also compared the OPPS median costs of those same procedures with the median costs of their APC groups, referred to as the OPPS-to-APC cost ratio. GAO's analysis of the ASC-to-APC and OPPS-to-APC cost ratios showed that 45 percent of all procedures in the analysis fell within a 0.10 point range of the ASC-to-APC median cost ratio, and 33 percent of procedures fell within a 0.10 point range of the OPPS-to-APC median cost ratio. These similar patterns of distribution around the median show that the APC groups reflect the relative costs of procedures provided by ASCs as well as they reflect the relative costs of procedures provided in hospital outpatient departments and can be used as the basis for the ASC payment system. GAO's analysis also identified differences in the cost of procedures in the two settings. The median cost ratio among all ASC procedures was 0.39 and when weighted by Medicare claims volume was 0.84. The median cost ratio for OPPS procedures was 1.04. Thus, the cost of procedures in ASCs is substantially lower than the corresponding cost in hospital outpatient departments.

Recommendations

Our recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.

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