Comparison of Comorbidity Treatment and Costs Associated With Bariatric Surgery Among Adults With Obesity in Canada

IMPORTANCE: Information on the associations between barriers to delivery of bariatric surgery and poor weight trajectory afterward is lacking. Estimates are needed to inform decisions by administrators and clinicians to improve care. OBJECTIVE: To estimate the difference in patient-years of treatment for diabetes, hypertension, and dyslipidemia and public-payer cost between the Canadian standard and an improved bariatric surgery care pathway. DESIGN, SETTING, AND PARTICIPANTS: Economic evaluation of a decision analytic model comparing the outcomes of the standard care in Canada with an improved bariatric care pathway with earlier sleeve gastrectomy delivery and better postsurgical weight trajectory. The model was informed by published clinical data (101 studies) and meta-analyses (11 studies) between January and May 2019. Participants were a hypothetical 100-patient cohort with demographic characteristics derived from a Canadian study. INTERVENTIONS: Reduction of Canadian mean bariatric surgery wait time by 2.5 years following referral and improvement of patient postsurgery weight trajectory to levels observed in other countries. MAIN OUTCOMES AND MEASURES: Modeling weight trajectory after sleeve gastrectomy and resolution rates for comorbidities in Canada in comparison with an improved care pathway to estimate differences in patient-years of comorbidity treatment over 10 years following referral and the associated costs. RESULTS: For the 100-patient cohort (mean [SD] 88.2% [1.4%] female; mean [SD] age, 43.6 [9.2] years; mean [SD] body mass index, 49.4 [8.2]; and mean [SD] comorbidity prevalence of 50.0% [4.1%], 66.0% [3.9%], and 59.3% [4.0%] for diabetes, hypertension, and dyslipidemia, respectively) over 10 years following referral, the improved vs standard care pathway was associated with median reduction in patient-years of treatment of 324 (95% credibility interval [CrI], 249-396) for diabetes, 245 (95% CrI, 163-356) for hypertension, and 255 (95% CrI, 169-352) for dyslipidemia, corresponding to total savings of $900 000 (95% CrI, $630 000 to $1.2 million) for public payers in the base case. Relative to standard of care, the associated reduction in costs was approximately 29% (95% CrI, 20%-42%) in the improved pathway. Sensitivity analyses demonstrated independent associations of earlier surgical delivery and various levels of postsurgical weight trajectory improvements with overall savings. CONCLUSIONS AND RELEVANCE: This study suggests that health care burden may be decreased through improvements to delivery and management of patients undergoing sleeve gastrectomy. More data are needed on long-term patient experience with bariatric surgery in Canada to inform better estimates.