Outcomes the Ontario Bariatric Network: a cohort study.

Background: Bariatric surgery centres of excellence are relatively new in Canada and were first started in Ontario in 2009. This study presents short-term outcomes of Canada's largest bariatric collaborative, from Ontario, during its first 3 years.

Methods: We performed a population-based cohort study that included all patients (age ≥ 18) who received a Roux-en-Y gastric bypass or sleeve gastrectomy for the purpose of weight loss from March 2009 to April 2012 within Ontario. Data were derived from the Canadian Institute for Health Information Discharge Abstract and Hospital Morbidity Databases. Primary outcomes included short-term overall complication rate, reoperation rate, anastomotic leak rate and death. Hierarchical logistic regression was used to identify risk factors for overall complications. A median odds ratio (OR) was used to compare risk-adjusted complication rates across centres of excellence.

Results: A total of 5007 procedures (91.7% Roux-en-Y gastric bypass, 8.3% sleeve gastrectomy) were performed during the 3-year study period, with an overall complication rate of 11.7% (95% confidence interval [CI] 10.8%-12.6%). The leak rate was 0.84% (95% CI 0.61%-1.13%), the reoperation rate was 4.6% (95% CI 4.0%-5.2%) and mortality was 0.16% (95% CI 0.07%-0.31%). Male sex, chronic kidney disease and osteoarthritis were identified as risk factors for overall complications ( value < 0.05). The median ORs across centres of excellence, calculated for both overall complications and reoperation rate, were 1.76 and 1.49, respectively.

Interpretation: Bariatric surgery within Ontario has similar short-term outcomes to those of other major world centres. The variability of outcomes within centres of excellence highlights areas for program quality improvement.