Comparing definitions of outpatient surgery: Implications for quality measurement

BackgroundAdverse event (AE) rates in outpatient surgery are inconsistently reported, partly because of the lack of a standard definition of outpatient surgery. We compared the types and rates of surgical procedures defined by two national healthcare agencies: Health Care Cost Institute (HCCI) and the Healthcare Cost and Utilization Project (HCUP) and considered implications for quality measurement.MethodsWe used HCCI and HCUP definitions to identify FY2012-14 VA outpatient surgeries.ResultsThere were six times as many HCCI surgeries as HCUP (6,575,830 versus 1,086,640). Ninety-nine percent of HCUP-defined surgeries were also identified by HCCI. More HCUP surgeries had higher average Medicare Relative Value Units then HCCI surgeries [5.3 (SD = 4.4) versus 1.6 (SD = 2.3) RVUs].ConclusionsRates and types of procedures vary widely between definitions. Quality measurement using HCCI versus HCUP may produce significantly lower AE rates because many of the surgeries included reflect low complexity and potentially low risk of AEs.