title: Specialty-specific trends in the prevalence and distribution of outpatient surgery: implications for payment and delivery system reforms.
abstract: BACKGROUND
  With nearly 53 million ambulatory procedures performed annually, future efforts to achieve greater value in surgical care should include a focus on outpatient surgery. To inform such efforts, a better understanding of specialty-specific trends in outpatient surgery is required.
  
  
  OBJECTIVE
  To assess the prevalence and distribution of outpatient surgery across specialties.
  
  
  METHODS
  Repeated cross-sectional.
  
  
  METHODS
  Using all-payer data from Florida (1998-2008), we identified physicians who performed one or more procedures. We assigned a specialty to each physician based on his procedure mix. After measuring the proportion of procedures performed on an outpatient basis, we assessed for specialty-specific changes over time in this proportion. Finally, we determined the frequency with which individual specialties used surgery centers for their outpatient care.
  
  
  RESULTS
  More than two thirds (67.8%) of all surgical procedures are carried out on an outpatient basis. The popularity of outpatient surgery has grown among many specialties over the past decade, including several (urology, gastroenterology, plastic surgery, and ophthalmology) that perform most of their cases in outpatient settings. Within surgical disciplines, overall trends in the use of outpatient surgery are strongly associated with the specialty's affinity for freestanding ambulatory surgery centers (Pearson's correlation coefficient = 0.76; P < .001).
  
  
  CONCLUSIONS
  A majority of surgeons in many specialties now provide predominantly outpatient care. Incorporating these findings into the design of future payment and delivery system reforms will help ensure adequate surgeon exposure to the efficiency gains that evolve from them.
authors.affiliation: University of Michigan, Ann Arbor, MI, USA kinks@med.umich.edu.
authors.forename: John M
authors.initials: JM
authors.lastname: Hollingsworth
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Birkmeyer
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Zaojun
authors.initials: Z
authors.lastname: Ye
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Miller
mesh_terms: D000556:Ambulatory Surgical Procedures / Q000191:economics* / Q000379:methods* / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D005431:Florida; D006801:Humans; D015995:Prevalence; D013043:Specialties, Surgical / Q000458:organization & administration*; D013531:Surgicenters / Q000458:organization & administration* / Q000706:statistics & numerical data
keywords: ambulatory surgical procedures; statistics and numerical data; surgicenters; utilization