Phentermine-topiramate and semaglutide cost-effective for adolescent obesity; access disparities limit health gains.
Background
The childhood obesity epidemic is exacerbated by inadequate access to care, despite recommendations for adolescent obesity treatments. The health-economic impact of unequal treatment access remains unclear, creating a critical gap in understanding the full value of interventions. This study addresses this by evaluating the cost-effectiveness of improving access to established adolescent obesity care and treatments, including pharmacotherapies like semaglutide, which targets the GLP-1 receptor to regulate appetite and metabolism.
Study Design
Researchers conducted an economic evaluation using a decision-analytic model to simulate a synthetic cohort of 1000 US adolescents, aged 12 to 26, on an annual basis. Modeled treatment strategies included phentermine-topiramate, semaglutide, bariatric surgery, and lifestyle modification (usual care). Primary analysis assumed perfect care access, while secondary analyses modeled imperfect access to primary care, specialty visits, and treatment initiation among groups stratified by insurance or race/ethnicity. Outcomes assessed were costs, health effects (averted obesity cases, quality-adjusted life years (QALYs)), and incremental cost-effectiveness ratios (ICERs).
Results
Under perfect access, phentermine-topiramate (vs. lifestyle modification) yielded an ICER of US$112,141/QALY. Subsequently, semaglutide (vs. phentermine-topiramate) showed an ICER of $166,513/QALY, both considered cost-effective under $200,000/QALY using 2025 pricing. However, under imperfect access, both cost-effectiveness and health gains were significantly reduced. Cost-effectiveness was reduced by 11%, and averted obesity cases decreased dramatically from 57% to 3% for semaglutide. Health gains were lowest among Medicaid-insured, Black, or Hispanic youth, highlighting significant disparities. ICERs were sensitive to medication characteristics such as costs, efficacy, discontinuation rates, and health utilities.
Semaglutideaverted 57% of obesity cases under perfect access, but only 3% under imperfect access.
Key Findings
- Phentermine-topiramate (vs. lifestyle) yielded an ICER of $112,141/QALY under perfect access.
- Semaglutide (vs. phentermine-topiramate) yielded an ICER of $166,513/QALY under perfect access.
- Both treatments were cost-effective under $200,000/QALY using 2025 pricing.
- Imperfect care access reduced cost-effectiveness by 11%.
- Averted obesity cases for semaglutide dropped from 57% to 3% under imperfect access, with lowest gains in Medicaid-insured, Black, or Hispanic youth.
Why It Matters
This economic evaluation provides crucial justification for the value of phentermine-topiramate and semaglutide in managing adolescent obesity, even at current pricing. For clinicians and policymakers, the findings underscore that simply having effective treatments is insufficient; improving care access is critical to realizing their full health-economic benefits. The stark reduction in averted obesity cases and health gains under imperfect access, particularly for vulnerable populations, highlights the urgent need for systemic changes to healthcare delivery. Addressing these access disparities could significantly impact the trajectory of the childhood obesity epidemic and improve long-term health outcomes, making these treatments more broadly impactful.
obesity
adolescent-obesity
cost-effectiveness
semaglutide
phentermine-topiramate
economic-evaluation