The impact of weight reduction surgery on health-care costs in morbidly obese patients

Background: The treatment of obesity and related comorbidities are significant financial burdens and sources of resource expenditure. This study was conducted in order to assess the impact of weight-reduction surgery on health-related costs. Methods: This was an observational two-cohort study. The treatment cohort included patients having undergone weight-reduction (bariatric) surgery at the McGill University Health Centre (MUHC) between 1986 and 2002. The control group included age and gender matched obese patients who had not undergone weight-reduction surgery from the Quebec provincial health insurance database (RAMQ). The cohorts were followed for a maximum of 5 years from inception. The primary outcome measure was overall direct health-care costs. Secondary outcomes included cost analysis by diagnostic category for the treatment of new medical conditions following cohort inception. Results: The cohorts were well-matched for age, gender and duration of follow-up. Patients having undergone bariatric surgery had significant reductions in mean percent initial excess weight loss (67.1%, P<0.001) and in percent change in initial body mass index (34.6%, P<0.001). Bariatric surgery patients had higher total costs for hospitalizations (per 1,000 patients) in the first year following cohort inception (surgery cohort = CDN $12,461,938; control cohort = CDN $3,609,680). At 5 years after cohort inception, average cumulative costs for operated patients were CDN $19,516,667 versus CDN $25,264,608, for an absolute difference of almost CDN $6,000,000 per 1,000 patients. Conclusion: Weight-reduction surgery in morbidly obese patients produces effective weight loss and decreases long-term direct health-care costs. The initial costs of surgery can be amortized over 3.5 years.