The cost-effectiveness of pharmacotherapy and lifestyle intervention in the treatment of obesity.

BACKGROUND: The Food and Drug Administration has approved several pharmacotherapies for the treatment of obesity. This study assesses the cost-effectiveness of six pharmacotherapies and lifestyle intervention for people with mild obesity (body mass indices [BMIs] 30 to 35). METHODS: A microsimulation model was constructed to compare seven weight loss strategies plus no treatment: intensive lifestyle intervention, orlistat, phentermine, phentermine/topiramate, lorcaserin, liraglutide, and semaglutide. Weight loss, quality-of-life scores, and costs were estimated using clinical trials and other published literature. Endpoints included costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) with a willingness-to-pay (WTP) threshold of $100 000/QALY. Results were analysed at 1-, 3-, and 5-year time horizons. RESULTS: At each of the three follow-up periods, phentermine was the cost-effective strategy, with ICERs of $46 258/QALY, $20 157/QALY, and $17 880/QALY after 1, 3, and 5 years, respectively. Semaglutide was the most effective strategy in the 3- and 5-year time horizons, with total QALYs of 2.224 and 3.711, respectively. However, the ICERs were prohibitively high at $1 437 340/QALY after 3 years and $576 931/QALY after 5 years. Deterministic and probabilistic sensitivity analyses indicated these results were robust. CONCLUSIONS: Phentermine is the cost-effective pharmacologic weight-loss strategy. Although semaglutide is the most effective, it is not cost-effective because of its high price.