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

Abstract

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.

Keywords: cost‐effectiveness analysis; obesity; pharmacotherapy; weight loss.

Conflict of interest statement

Dr Hur received consulting fees from Novo Nordisk outside the submitted work. Dr Corey received consulting fees from Bristol Myers Squibb, Novo Nordisk, and Gilead outside the submitted work and grant funding from Bristol Myers Squibb and Boehringer‐Ingelheim. Dr Kaplan is a consultant to Novo Nordisk. Novo Nordisk manufactures liraglutide and semaglutide.

© 2019 The Authors. Obesity Science & Practice published by John Wiley & Sons Ltd, World Obesity and The Obesity Society.

Figures

Figure 1

Base case results in cost‐effectiveness planes after (A) 1 year, (B) 3 years, and (C) 5 years. The dashed lines indicate the efficiency frontiers. PHEN/TPM, phentermine/topiramate

Figure 2

One‐way sensitivity analyses depicted as tornado diagrams. Range in semaglutide incremental cost‐effectiveness ratios (ICERs) when comparing phentermine vs semaglutide after (A) 3 years and (B) 5 years

Figure 3

Probabilistic sensitivity analyses results depicted as acceptability curves after (A) 1 year, (B) 3 years, and (C) 5 years. The dashed line indicates the base case willingness‐to‐pay threshold. PHEN/TPM, phentermine/topiramate

Figure 4

Probabilistic sensitivity analyses depicted in cost‐effectiveness planes after (A) 1 year, (B) 3 years, and (C) 5 years. PHEN/TPM, phentermine/topiramate