title: The effect of the Ontario Bariatric Network on health services utilization after bariatric surgery: a retrospective cohort study.
abstract: BACKGROUND
  In 2009, the Ontario Bariatric Network was established to address the exploding demand by Ontario residents for bariatric surgery services outside Canada. We compared the use of postoperative hospital services between out-of-country surgery recipients and patients within the Ontario Bariatric Network.
  
  
  METHODS
  We conducted a population-based, comparative study using administrative data held at the Institute for Clinical Evaluative Sciences. We included Ontario residents who underwent bariatric surgery between 2007 and 2012 either outside the country or at one of the Ontario Bariatric Network's designated centres of excellence. The primary outcome was use of hospital services in Ontario within 1 year after surgery.
  
  
  RESULTS
  A total of 4852 patients received bariatric surgery out of country, and 5179 patients underwent surgery through the Ontario Bariatric Network. After adjustment, surgery at a network centre was associated with a significantly lower utilization rate of postoperative hospital services than surgery out of country (rate ratio 0.90, 95% confidence interval [CI] 0.84 to 0.97). No statistically significant differences were found with respect to time in critical care or mortality. However, the physician assessment and reoperation rates were significantly higher among patients who received surgery at a network centre than among those who had bariatric surgery out of country (rate ratio 4.10, 95% CI 3.69 to 4.56, and rate ratio 1.84, 95% CI 1.34 to 2.53, respectively).
  
  
  CONCLUSIONS
  The implementation of a comprehensive, multidisciplinary provincial program to replace outsourcing of bariatric surgical services was associated with less use of postoperative hospital services by Ontario residents undergoing bariatric surgery. Future research should include an economic evaluation to determine the costs and benefits of the Ontario Bariatric Network.
authors.affiliation: Department of Surgery (Elnahas, Jackson, Okrainec, Urbach), Department of Medicine (Bell) and Institute of Health Policy, Management and Evaluation (Elnahas, Austin, Bell, Urbach), University of Toronto; Institute for Clinical Evaluative Sciences (Austin, Urbach), Toronto, Ont.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Elnahas
authors.affiliation: Department of Surgery (Elnahas, Jackson, Okrainec, Urbach), Department of Medicine (Bell) and Institute of Health Policy, Management and Evaluation (Elnahas, Austin, Bell, Urbach), University of Toronto; Institute for Clinical Evaluative Sciences (Austin, Urbach), Toronto, Ont.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Jackson
authors.affiliation: Department of Surgery (Elnahas, Jackson, Okrainec, Urbach), Department of Medicine (Bell) and Institute of Health Policy, Management and Evaluation (Elnahas, Austin, Bell, Urbach), University of Toronto; Institute for Clinical Evaluative Sciences (Austin, Urbach), Toronto, Ont.
authors.forename: Allan
authors.initials: A
authors.lastname: Okrainec
authors.affiliation: Department of Surgery (Elnahas, Jackson, Okrainec, Urbach), Department of Medicine (Bell) and Institute of Health Policy, Management and Evaluation (Elnahas, Austin, Bell, Urbach), University of Toronto; Institute for Clinical Evaluative Sciences (Austin, Urbach), Toronto, Ont.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Austin
authors.affiliation: Department of Surgery (Elnahas, Jackson, Okrainec, Urbach), Department of Medicine (Bell) and Institute of Health Policy, Management and Evaluation (Elnahas, Austin, Bell, Urbach), University of Toronto; Institute for Clinical Evaluative Sciences (Austin, Urbach), Toronto, Ont.
authors.forename: Chaim M
authors.initials: CM
authors.lastname: Bell
authors.affiliation: Department of Surgery (Elnahas, Jackson, Okrainec, Urbach), Department of Medicine (Bell) and Institute of Health Policy, Management and Evaluation (Elnahas, Austin, Bell, Urbach), University of Toronto; Institute for Clinical Evaluative Sciences (Austin, Urbach), Toronto, Ont.
authors.forename: David R
authors.initials: DR
authors.lastname: Urbach