Risk of Relapse among Medicare Advantage Members Diagnosed with Schizophrenia and Receiving Once-monthly Paliperidone Palmitate or First Generation Long-acting Injectable Antipsychotics

Abstract: Assessment of real-world outcomes associated with different antipsychotics helps inform treatment selection for patients with schizophrenia. This real-world study aimed to compare outcomes of patients with schizophrenia treated with once-monthly paliperidone palmitate (PP1M) vs. first-generation long-acting injectable (FGLAI) antipsychotics. Eligible patients with schizophrenia new to long-acting injectable antipsychotics who initiated PP1M or a FGLAI were identified from Medicare Advantage claims from Optum’s de-identified Clinformatics® Data Mart Database (2009-01-01 to - 2023-06-30). Patients were followed from treatment initiation (index date) until the end of continuous insurance enrollment. Relapse, a composite measure defined as schizophrenia-related hospitalization or emergency department event, was evaluated. To minimize confounding, a standardized mortality ratio weight-based propensity score was applied. Relapse rates were assessed using Poisson regression; time-to-first relapse was evaluated using Kaplan-Meier and Cox estimates. The final sample included 870 and 1,801 patients newly initiated on PP1M and FGLAI, respectively. The PP1M cohort was younger and had lower baseline comorbidity. Relapse events within 90-days pre-index were more prevalent for the PP1M (40.5%) versus the FGLAI (26.6%) cohort. Relapse rate during the follow up was lower for the PP1M versus the FGLAI cohorts (35.3 vs 62.8 per 100 patient years; IRR (0.56, [95% CI:0.40-0.71]). Median time-to-first relapse was 1,772 days for the PP1M cohort vs 816 days for the FGLAI cohort (p