Systematic assessment of decision analytic models for the cost-effectiveness of bariatric surgery for morbid obesity

Bariatric surgery among patients with morbid obesity is very effective for providing long-term weight loss and remission of obesity-related co-morbidities. However, it is very expensive and its cost effectiveness is commonly argued. Long-term cost-effectiveness evaluations of bariatric surgery have often relied on decision models. A systematic review was performed on the methodologic approaches and their quality, evaluated the quality of reporting, and summarized findings and conclusions in published cost-effectiveness models of bariatric surgery for morbid obesity. A search from different databases with an end date of October 15, 2017 was completed. The initial search for title and abstract screening resulted in 741 articles. A total of 50 articles were included for full-text review and 23 economic evaluation studies were included in the systematic review. The reporting quality scores of most articles were rated as acceptable between 61% and 100%. Most studies (89%) were modeled for adult patients with age range between 25 and 75 years old. Sixty-one percent of studies defined their health states by the existence or absence of different obesity-related co-morbidities. Eleven percent of studies took the societal perspective. Most studies (61%) used a lifetime horizon. Thirty-nine percent of studies identified the extent of weight loss as the most sensitive and influential parameter. Seventeen (74%) did not report a formal model validation. Laparoscopic Roux-en-Y gastric bypass was reported as the most cost-effective strategy most often when it compared with no treatment or medical management. While most had acceptable quality of reporting levels, several gaps in the quality of reporting and quality of methods emerged, which led to recommendations for how to improve quality in future studies.