AbstractBackgroundThe objective of the study was to evaluate the cost–utility of bariatric surgery in England.MethodsA state-transition Markov model was developed to compare the costs and outcomes of two treatment approaches for patients with morbid obesity: bariatric surgery, including gastric bypass, sleeve gastrectomy and adjustable gastric banding; and non-surgical usual care. Parameters of the effectiveness of surgery and complications were informed by data from the UK National Bariatric Surgery Registry, the Scandinavian Obesity Registry and the Swedish Obese Subjects study. Costs and utilities were informed by UK sources.ResultsBariatric surgery was associated with reduced mean costs to the health service by €2742 (£1944), and gain of 0·8 life-years and 4·0 quality-adjusted life-years (QALYs) over a lifetime compared with usual care. Bariatric surgery also had the potential to reduce the lifetime risks of obesity-related cardiovascular diseases and diabetes. Delaying surgery for up to 3 years resulted in a reduction of 0·7 QALYs and a minor decrease of €2058 (£1459) in associated healthcare costs.ConclusionCurrently used surgical methods were found to be cost saving over the lifetime of individuals treated in England.