title: Ambulatory surgery centers and outpatient urologic surgery among Medicare beneficiaries.
abstract: OBJECTIVE
  To determine the effect of an ambulatory surgery center (ASC) opening in a healthcare market on utilization and quality of outpatient urologic surgery.
  
  
  METHODS
  This is a retrospective cohort study of Medicare beneficiaries undergoing outpatient urologic surgery from 2001 to 2010. Markets were classified into 3 groups based on ASC status (ie, those with ASCs, those without ASCs, and those where ASCs were introduced). Multiple propensity score methods adjusted for differences between markets and general linear mixed models determined the effect of ASC opening on utilization and quality, defined by mortality and hospital admission within 30 days of the index procedure.
  
  
  RESULTS
  During the study period, 195 ASCs opened in markets previously without one. Rates of hospital-based urologic surgery in markets where ASCs were introduced declined from 221 to 214 procedures per 10,000 beneficiaries in the 4 years after baseline. In contrast, rates in the other 2 market types increased over the same period (P<.001). Rates of outpatient urologic surgery overall (ie, in the hospital and ASC) demonstrated similar growth across market types during same period (P=.56). The introduction of an ASC into a market was not associated with increases in hospital admission or mortality (P>.5).
  
  
  CONCLUSIONS
  The introduction of an ASC into a healthcare market lowered rates of outpatient urologic surgery performed in the more expensive hospital setting. This redistribution was not associated with declines in quality or with greater growth in overall outpatient surgery use.
authors: Department of Urology, Dow Division of Health Services Research The University of Michigan, Ann Arbor, MI.
authors: Anne M
authors: AM
authors: Suskind
authors: Department of Urology, Dow Division of Health Services Research The University of Michigan, Ann Arbor, MI.
authors: Rodney L
authors: RL
authors: Dunn
authors: Department of Urology, Dow Division of Health Services Research The University of Michigan, Ann Arbor, MI.
authors: Yun
authors: Y
authors: Zhang
authors: Department of Urology, Dow Division of Health Services Research The University of Michigan, Ann Arbor, MI.
authors: John M
authors: JM
authors: Hollingsworth
authors: Department of Urology, Dow Division of Health Services Research The University of Michigan, Ann Arbor, MI. Electronic address: suskina@med.umich.edu.
authors: Brent K
authors: BK
authors: Hollenbeck
mesh_terms: D000368:Aged; D000556:Ambulatory Surgical Procedures / Q000592:standards* / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D006278:Medicare; D011787:Quality of Health Care; D012189:Retrospective Studies; D013531:Surgicenters; D014481:United States; D013520:Urologic Surgical Procedures / Q000592:standards* / Q000706:statistics & numerical data*