title: Physician ownership of ambulatory surgery centers and practice patterns for urological surgery: evidence from the state of Florida.
abstract: OBJECTIVE
  To evaluate the relationship between ownership and use of ambulatory surgical centers (ASCs).
  
  
  METHODS
  From 1998 through 2002, ambulatory surgical discharges for procedures within the genitourinary system were abstracted from the Florida State Ambulatory Surgery Database. State-wide utilization rates for ambulatory surgery were calculated by physician-level ownership (using an empirically-derived, externally-validated method) and financial incentives. A surgeon-level Poisson regression model was fit to compare the rates of surgery by year, ownership, and their interaction.
  
  
  RESULTS
  Rates of ambulatory surgery increased from 607 per 100,000 in 1998 to 702 per 100,000 in 2002 (P < 0.01 for trend). Although rates at the hospital increased only slightly (0.9%), those at the ASC were up by 53% (P < 0.01). Physician ownership was associated with this greater utilization as new owners increased their use from 9 per 100,000 to 94 per 100,000 (P < 0.01) in the first full year as owners. In the first year of ownership, the proportion of a new owner's surgeries comprising of financially lucrative procedures increased to 61% compared with 50% in the year preceding ownership (P < 0.01).
  
  
  CONCLUSIONS
  Physician ownership is associated with the increasing use of ASCs, although the extent to which this is attributable to previously unmet demand is unclear. However, new owners seem to alter their procedure mix after establishing ownership to include a greater share of financially lucrative procedures.
authors.affiliation: Department of Urology, Division of Health Services Research, University of Michigan Health System, Ann Arbor, Michigan, USA.
authors.forename: Seth A
authors.initials: SA
authors.lastname: Strope
authors.forename: Stephanie
authors.initials: S
authors.lastname: Daignault
authors.forename: John M
authors.initials: JM
authors.lastname: Hollingsworth
authors.forename: Zaojun
authors.initials: Z
authors.lastname: Ye
authors.forename: John T
authors.initials: JT
authors.lastname: Wei
authors.forename: Brent K
authors.initials: BK
authors.lastname: Hollenbeck