AIMS: To characterize switching among GLP-1 receptor agonists (GLP-1 RAs) in a large private-sector cohort in Poland and to quantify therapy- and patient-level associations with switching while accounting for switching opportunity and calendar-time dynamics.
METHODS: We conducted a retrospective analysis of GLP-1 RA prescription records from the LUX MED network (2018-2025). Switching was defined as any change in agent between consecutive prescriptions. Patients with more than one prescription were included (n = 42,423). The primary analysis used a transition-level discrete-time hazard model in which each prescription-to-prescription interval contributed one observation, and the outcome was switching at that interval. Current-therapy contrasts were reported relative to subcutaneous semaglutide. Sensitivity analyses examined alternative temporal parameterizations and additional adjustment for elapsed time.
RESULTS: Overall, 29.7% of patients switched at least once and 14.3% switched two or more times. In the transition-level analysis, 12,620 patients contributed 27,095 transitions. After adjustment for opportunity and calendar time, liraglutide was associated with substantially lower odds of switching compared with subcutaneous semaglutide (OR, 0.02; 95% CI, 0.01-0.03), whereas oral semaglutide (OR, 1.30; 95% CI, 0.78-2.17) and dulaglutide (OR, 1.70; 95% CI, 0.95-3.04) did not differ significantly. Temporal analyses revealed peaks consistent with episodic substitution and accelerated tirzepatide uptake after market entry. The principal associations remained directionally consistent in sensitivity analyses.
CONCLUSIONS: Switching among GLP-1 RAs is common and time-dependent. Time-aware modelling identified therapy-specific switching patterns and pronounced temporal variation; reasons for switching remain unmeasured, and the observed associations should be interpreted as hypothesis-generating.
Authors
Łupina, Krzysztof; Dziewierz, Artur; Janczura, Jakub; Siudak, Zbigniew