Authors: R Khandker, B Mohit, E Fonseca, S Fleming, M Tan, W Quan, T LeMasters, J Schmier
Published: Schizophrenia Research, 2025
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Background
Patients with schizophrenia commonly experience treatment discontinuation/switching, which can result in relapse and high healthcare burden. This study examined associations between antipsychotic discontinuation/switching and weight gain risk (WGR), patient-level characteristics and treatment modalities, including oral antipsychotic (OA) versus long-acting injectable (LAI).
Methods
This retrospective cohort study identified adults diagnosed with schizophrenia, filling an antipsychotic prescription between 1/1/2017-12/31/2019 using the Merative® MarketScan® Multi-State Medicaid administrative claims database. The index date was the first antipsychotic prescription fill date following schizophrenia diagnosis. Associations with discontinuation (≥60-day gap in therapy) and switching (antipsychotic change) were assessed using Kaplan Meier and multivariate Cox proportional hazard regression.
Results
Among 6987 patients, 16.8 %, 63.2 %, and 20.0 %, respectively, were indexed on low, medium, and high WGR antipsychotics, while 33.5 % received LAI and 66.5 % OA. More patients on low WGR discontinued than those on medium and high WGR antipsychotics (17.8 % vs. 12.5 % and 12.0 %, respectively, p < 0.001). More patients on OA versus LAI (16.8 % vs. 6.4 %, p < 0.001) discontinued. Time-to-discontinuation was significantly longer on LAI vs. OA (249.5 vs. 90.0 days, p < 0.001). More patients on medium (52.3 %) and high (54.9 %) WGR switched than on low WGR antipsychotics (46.1 %) (p < 0.001). Patients on LAI antipsychotics had half the hazard of discontinuation (hazard ratio [HR]: 0.53; 95 % CI: 0.47-0.59, p < 0.001) than on OA.
Conclusions
Discontinuation occurred more frequently among patients taking OAs, while switching occurred more frequently among patients taking higher WGR antipsychotics. Schizophrenia treatment is complex and needs effective treatment options with increased treatment persistence to reduce disease burden.
