Factors Associated With Semaglutide Initiation Among Adults With Obesity

Abstract

Importance: Semaglutide, a novel glucagon-like peptide-1 (GLP-1) receptor agonist medication, was approved for weight management in individuals with obesity in June 2021. There is limited evidence on factors associated with uptake among individuals in this subgroup without diabetes.

Objective: To explore factors associated with semaglutide initiation among a population of commercially insured individuals with obesity but no diagnosed diabetes.

Design, setting, and participants: This retrospective observational cohort study used data from the Merative MarketScan Commercial Claims and Encounters Database and included adults in the US aged 18 years or older with a first diagnosis of obesity in an outpatient or inpatient setting between June 5, 2021, and July 1, 2022. Inclusion criteria were no prior antiobesity medication, GLP-1, bariatric surgery, or diabetes-related claim in the 12 months prior to obesity diagnosis, and continuous enrollment in the 12 months preceding and 6 months following obesity diagnosis. Analysis was conducted from February to November 2024.

Exposures: Medication classes prescribed, clinical diagnoses, and sociodemographic factors. Exposures were identified within the 12 months prior to obesity diagnosis.

Main outcomes and measures: Factors associated with incident semaglutide prescription within 6 months after obesity diagnoses were identified using a 10-fold cross-classified random forest model. The top 20 features of the model feature importance list were ranked in a Shapley Additive Explanations plot and used in a multivariable logistic regression model to quantify associations with semaglutide initiation.

Results: In this study of 97 456 individuals, 58 124 (59.6%) were female, 26 582 (27.3%) were aged 45 to 54 years, 50 705 (52.0%) resided in the South region, and 49 390 (50.7%) were covered by preferred provider organization plans. Of all participants, 1963 (2.0%) initiated semaglutide within 6 months of their initial obesity diagnosis. The random forest model had an area under the receiver operating characteristic curve of 0.71 (95% CI, 0.69-0.74). The most important exposures identified via Shapley Additive Explanations were sex, use of antidepressants, and employer industry. The top 20 factors were used in the logistic regression model, and significant associations were found with semaglutide initiation, including being female (adjusted odds ratio [aOR], 2.30; 95% CI, 2.05-2.58), use of certain medication classes including antidepressants (aOR,1.62; 95% CI, 1.46-1.78), and being covered by a point-of-service plan (aOR, 1.78; 95% C, 1.42-2.22).

Conclusions and relevance: This cohort study found that key sociodemographic, health care, and clinical factors are associated with receipt of semaglutide in those without diabetes. These findings suggest that insurance plan type and structure may be a crucial intervention point for improving equity in obesity treatment access.

Figure 1.. Mean Shapley Additive Explanation (SHAP) Value Summary From Cross-Classified Random Forest Model Estimating Semaglutide Initiation Among Individuals With Obesity Without Diabetes

SHAP value plots for each feature are shown, ranked by importance (mean absolute SHAP value). Each dot represents 1 individual, with their position representing their SHAP value. Color is used to indicate the specified feature characteristic. Red dots indicate those who have the listed characteristic, while blue dots indicate those who do not. For example, for the characteristic female, individuals with a red dot are female and appear predominantly to the right, indicating that they are more likely to initiate semaglutide, while those with a blue dot are male. Age is a continuous variable representing age at diagnosis (18 to 64 years) and index month ranged from June 2021 to June 2022. MSA indicates metropolitan statistical area; NEC, not elsewhere classified; PPO, preferred provider organization.

Figure 2.. Adjusted Odds Ratios (ORs) of Top Features for Semaglutide Initiation

CDHP indicates consumer-directed health plan; EPO, exclusive provider organization; HDHP, high deductible health plan; HMO, health maintenance organization; MSA, metropolitan statistical area; NEC, not elsewhere classified; POS, point of service; PPO, preferred provider organization.