title: Ambulatory Surgery Centers and Their Intended Effects on Outpatient Surgery.
abstract: OBJECTIVE
  To assess the impact of ambulatory surgery centers (ASCs) on rates of hospital-based outpatient procedures and adverse events.
  
  
  METHODS
  Twenty percent national sample of Medicare beneficiaries.
  
  
  METHODS
  A retrospective study of beneficiaries undergoing outpatient surgery between 2001 and 2010. Health care markets were sorted into three groups-those with ASCs, those without ASCs, and those where one opened for the first time. Generalized linear mixed models were used to assess the impact of ASC opening on rates of hospital-based outpatient surgery, perioperative mortality, and hospital admission.
  
  
  RESULTS
  Adjusted hospital-based outpatient surgery rates declined by 7 percent, or from 2,333 to 2,163 procedures per 10,000 beneficiaries, in markets where an ASC opened for the first time (p < .001 for test between slopes). Within these markets, procedure use at ASCs outpaced the decline observed in the hospital setting. Perioperative mortality and admission rates remained flat after ASC opening (both p > .4 for test between slopes).
  
  
  CONCLUSIONS
  The opening of an ASC in a Hospital Service Area resulted in a decline in hospital-based outpatient surgery without increasing mortality or admission. In markets where facilities opened, procedure growth at ASCs was greater than the decline in outpatient surgery use at their respective hospitals.
authors: Institute for Healthcare Policy and Innovation, University of Michigan, Ann Arbor, MI.
authors: Brent K
authors: BK
authors: Hollenbeck
authors: Dow Division of Urology, University of Michigan, Ann Arbor, MI.
authors: Rodney L
authors: RL
authors: Dunn
authors: Department of Urology, UCSF, San Francisco, CA.
authors: Anne M
authors: AM
authors: Suskind
authors: Department of Urology, Washington University, Medical Building One, Barnes-Jewish West County Hospital, Creve Coeur, MO.
authors: Seth A
authors: SA
authors: Strope
authors: Dow Division of Urology, University of Michigan, Ann Arbor, MI.
authors: Yun
authors: Y
authors: Zhang
authors: Institute for Healthcare Policy and Innovation, University of Michigan, Ann Arbor, MI.
authors: John M
authors: JM
authors: Hollingsworth
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000556:Ambulatory Surgical Procedures / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data; D010343:Patient Admission / Q000706:statistics & numerical data; D019984:Quality Indicators, Health Care; D011787:Quality of Health Care / Q000706:statistics & numerical data*; D012111:Residence Characteristics; D012189:Retrospective Studies; D012959:Socioeconomic Factors; D013531:Surgicenters / Q000706:statistics & numerical data*; D014481:United States
keywords: Ambulatory surgery; ambulatory surgery center; utilization
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