A comprehensive cost-effectiveness analysis published today in JAMA Health Forum revealed that while newer antiobesity medications such as tirzepatide and semaglutide offer substantial long-term health benefits, they do not meet standard cost-effectiveness thresholds at their current net prices.
The study, conducted by researchers from the University of Chicago, utilized the validated Diabetes, Obesity, Cardiovascular Disease Microsimulation (DOC-M) model to project lifetime health outcomes and economic impacts for 126 million eligible U.S. adults.
Over a lifetime, tirzepatide would avert 45,609 obesity cases per 100,000 individuals, while semaglutide would prevent 32,087 cases per 100,000 individuals. Both medications demonstrated significant reductions in diabetes and cardiovascular disease incidence compared with lifestyle modification alone.
"Efforts to reduce the net prices of new antiobesity medications are essential to ensure equitable access to highly effective antiobesity medications," the researchers concluded.
Detailed Findings
Led by Jennifer H. Hwang, the analysis evaluated the lifetime health effects and cost-effectiveness of four antiobesity medications—tirzepatide, semaglutide, phentermine-topiramate, and naltrexone-bupropion—combined with lifestyle modification vs. lifestyle modification alone.
Despite generating the largest incremental quality-adjusted life-year (QALY) gains among all medications studied—0.35 for tirzepatide and 0.25 for semaglutide—their incremental cost-effectiveness ratios were $197,023/QALY and $467,676/QALY, respectively. These values significantly exceed the commonly accepted threshold of $100,000/QALY.
To reach cost-effectiveness, the net prices would require substantial discounts—30.5% for tirzepatide and 81.9% for semaglutide from their current estimated net prices.
Among the medications studied, only naltrexone-bupropion was found to be cost-saving due to its lower cost, with an 89.1% probability of being cost-effective at the $100,000/QALY threshold.
Clinical Impact and Cost Implications
The study projects that tirzepatide would reduce 20,854 incident cases of diabetes per 100,000 individuals and 10,655 cardiovascular disease cases. Semaglutide showed similar but slightly lower efficacy: It was projected to reduce 19,211 diabetes cases and 8,263 cardiovascular disease cases per 100,000 individuals.
These medications also demonstrated significant reductions in mortality. Tirzepatide was projected to prevent 1,495 diabetes-related deaths and 2,897 cardiovascular disease-related deaths per 100,000 individuals over a lifetime.
The researchers utilized SSR Health data to estimate net prices for semaglutide and tirzepatide, which reflects rebates and discounts across various insurance programs. For tirzepatide and semaglutide, the annual net price estimates were $6,236 and $8,412, respectively.
Methodology
The study cohort included 4,823 individuals representing 126 million eligible U.S. adults aged 20 to 79 years who would meet clinical trial inclusion criteria for antiobesity medications. The mean age was 48 years, 51% were female, the initial mean BMI was 34.7, and 85% had at least one weight-related comorbidity.
The DOC-M model incorporated medication-specific effects on weight and six cardiometabolic risk factors, medication-specific adverse events that affected quality of life, and discontinuation rates based on clinical trial evidence.
The researchers performed probabilistic sensitivity analyses based on 1,000 Monte Carlo simulations to account for parameter uncertainty simultaneously.
Implications for Policy and Practice
The findings support ongoing efforts to reduce the prices of new antiobesity medications. This study adds to the growing body of evidence suggesting that while these medications provide substantial clinical benefits, their current pricing poses significant barriers to access and widespread adoption.
As the researchers stated: "These high net prices will likely exacerbate obesity disparities, disproportionately affecting racial and ethnic groups with unequal health care access."
They suggested that policy solutions, including Medicare price negotiations under the Inflation Reduction Act and alternative weight maintenance approaches after initial weight loss, could help improve affordability and accessibility of obesity treatment.
Conflict of interest disclosures can be found in the study.