The effect of health system factors on outcomes and costs after bariatric surgery in a universal healthcare system: a national cohort study of bariatric surgery in Canada.

Introduction: Previous data demonstrate that patients who receive bariatric surgery at a Center of Excellence are different than those who receive care at non-accredited centers. Canada provides a unique opportunity to naturally exclude confounders such as insurance status, hospital ownership, and lack of access on comparisons between hospitals and surgeons in bariatric surgery outcomes. The objective of this study was to determine the effect of hospital accreditation and other health system factors on all-cause morbidity after bariatric surgery in Canada.

Methods: This was a population-based study of all patients aged ≥18 who received a bariatric procedure in Canada (excluding Quebec) from April 2008 until March 2015. The main outcomes for this study were all-cause morbidity and costs during the index admission. All-cause morbidity included any documented complication which extended length of stay by 24 h or required reoperation. Risk-adjusted hierarchical regression models were used to determine predictors of morbidity and cost.

Results: Overall, 18,398 patients were identified and the all-cause morbidity rate was 10.1%. Surgeon volume and teaching hospitals were both found to significantly decrease the odds of all-cause morbidity. Specifically, for each increase in 25 bariatric cases per year, the odds of all-cause morbidity was 0.94 times lower (95% CI 0.87-1.00, p = 0.03). Teaching hospitals conferred a 0.75 lower odds of all-cause morbidity (95% CI 0.58-0.95, p < 0.001). Importantly, formal accreditation was not associated with a decrease in all-cause morbidity within a universal healthcare system. No health system factors were associated with significant cost differences.

Conclusion: This national cohort study found that surgeon volume and teaching hospitals predicted lower all-cause morbidity after surgery while hospital accreditation was not a significant factor.