Real-World Adherence Patterns and Predictors of GLP-1 Receptor Agonist Use for Obesity Management in a Medicaid Population

Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have emerged as effective anti-obesity medications (AOMs); however, real-world adherence and persistence patterns among Medicaid populations remain poorly understood, specifically after medication shortage resolution. This study examined adherence and persistence to GLP-1 RA AOMs among Mississippi (MS) Medicaid members following statewide coverage initiation in July 2023. This cohort study utilized MS Medicaid claims data from January 2023 to December 2025. Members aged ≥ 18 years initiating GLP-1 RA AOMs between July 2023 and June 2025, with 6 months of continuous enrollment pre- and post-initiation, were included. Adherence rate was defined as percentage of members with proportion of days covered (PDC) greater than 0.8, and persistence rate was defined as percentage of members with continuous therapy without a 60-day gap, evaluated at 3- and 6-month intervals. Group-based trajectory modeling (GBTM) identified distinct adherence trajectories, and multinomial logistic regression assessed predictors of trajectory membership. A subgroup analysis was conducted for members initiating between July 2023 and December 2024, who had 12-month follow-up period. The final analytic cohort included 3968 members, predominantly female (92.52%), Black (50.28%), and younger adults (18–39 years; 61.95%). Adherence rates declined from 56.85% at 3 months to 38.16% at 6 months, with persistence rates decreasing from 72.98% to 51.03% over the same period. In the 12-month subgroup analysis, adherence and persistence rates declined to 25.26% and 36.67%, respectively. GBTM identified five trajectories: consistent adherent (52.27%), delayed decliner (13.53%), consistent decliner (12.85%), fluctuating adherent (11.14%), and rapid discontinuer (10.21%). Treatment initiation in 2023, younger age, Black race, type 2 diabetes mellitus, and cardiovascular comorbidities were associated with suboptimal adherence trajectories, while managed care organization enrollment and hypertension were protective. GLP-1 RA AOM adherence declines substantially over time among MS Medicaid members. Targeted interventions are needed to sustain long-term therapeutic engagement.