title: Comparing definitions of outpatient surgery: Implications for quality measurement.
abstract: BACKGROUND
  Adverse 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.
  
  
  METHODS
  We used HCCI and HCUP definitions to identify FY2012-14 VA outpatient surgeries.
  
  
  RESULTS
  There 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].
  
  
  CONCLUSIONS
  Rates 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.
authors.affiliation: Center for Healthcare Organization and Implementation Research (CHOIR), VA Boston Healthcare System, Boston, MA, USA; Department of Surgery, Boston University School of Medicine, Boston, MA, USA. Electronic address: hillary.mull@va.gov.
authors.forename: Hillary J
authors.initials: HJ
authors.lastname: Mull
authors.affiliation: Center for Healthcare Organization and Implementation Research (CHOIR), VA Boston Healthcare System, Boston, MA, USA; Healthcare Administration, Sawyer Business School Suffolk University, Boston, MA, USA.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Rivard
authors.affiliation: Partnered Evidence-based Policy Resource Center (PEPReC), Department of Veterans Affairs, Boston, MA, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Legler
authors.affiliation: Partnered Evidence-based Policy Resource Center (PEPReC), Department of Veterans Affairs, Boston, MA, USA; Northeastern University School of Pharmacy, Boston, MA, USA.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Pizer
authors.affiliation: Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA; Center for Surgical, Medical Acute Care Research and Transitions (C-SMART), Birmingham VA Medical Center, Birmingham, AL, USA.
authors.forename: Mary T
authors.initials: MT
authors.lastname: Hawn
authors.affiliation: Department of Surgery, Boston University School of Medicine, Boston, MA, USA; Department of Surgery, VA Boston Healthcare System, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
authors.forename: Kamal M F
authors.initials: KMF
authors.lastname: Itani
authors.affiliation: Center for Healthcare Organization and Implementation Research (CHOIR), VA Boston Healthcare System, Boston, MA, USA; Department of Surgery, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Amy K
authors.initials: AK
authors.lastname: Rosen
mesh_terms: D000368:Aged; D000556:Ambulatory Surgical Procedures / Q000009:adverse effects / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D011785:Quality Assurance, Health Care; D009626:Terminology as Topic
keywords: Ambulatory surgery; Measurement; Patient safety; Quality improvement; Quality measurement; Veterans