Selected reviews of Economic Evaluations relating to Diabetes and Obesity

Study Question: Although obesity is expensive and bariatric surgery is effective, the costs of bariatric surgery are high. Recent studies have described the impact of bariatric surgery on health care costs, quality of life, and have assessed cost-effectiveness, but most have employed simulation models. The aim of this study was to assess the cost, quality of life impact, and the cost-utility of bariatric surgery in a managed care population between 2001 and 2005. In order to do this, empiric data were used from a single managed care health plan, and seven Bariatric Surgery Centres of Excellence. Patient Group: 221 adult patients in a managed care population who underwent bariatric surgery between 2001 and 2005. There were a number of inclusion/exclusion criteria. The analysis was based on medical claims data for all patients and survey data for 122 survey respondents (55% response rate). Patients were generally middle-aged (mean age at surgery, 42 yrs), female (88%), and white (86%). Sixty-four percent underwent open and 33% underwent laparoscopic Roux-en-Y procedures. Key Results: One year after surgery, mean body mass index fell from 51 to 31 kg/m(2) in women and from 59 to 35 kg/m(2) in men, with substantial improvements in comorbidities. Postsurgical mortality and morbidity were low. Total per member per month costs increased in the six months before bariatric surgery, were lower in the 12 months after bariatric surgery, but increased somewhat over the next 12 months. The average cost of bariatric surgery was US$11,144. The average cost of laparoscopic surgery was US$10,393 compared with US$11,705 for open surgery. When presurgical quality of life was assessed prospectively, average health utility scores improved by 0.14 one year after surgery. In analyses that took a lifetime time horizon, projected future costs based on age and obesity, and discounted costs and health utilities at 3% per year, the cost-utility ratio for bariatric surgery versus no surgery was approximately US$1,400 per QALY gained. In sensitivity analyses, bariatric surgery was more cost-effective in women, non-whites, more obese patients, and when performed laparoscopically. Based on these findings, the authors conclude that, although not cost-saving, bariatric surgery represents very good value for money. Its long-term costeffectiveness appears to depend on the natural history and cost of late postsurgical complications and the natural history and cost of untreated morbid obesity.