Medication discontinuation with depot and oral antipsychotics in outpatients with schizophrenia: comparison of matched cohorts from a 12-month observational study

Summary Aims: This study compared all‐cause medication discontinuation (any switch, augmentation or medication discontinuation) in matched cohorts of patients with schizophrenia who were initiated on depot or oral antipsychotics. Other objectives included between‐group comparisons of resource use, and clinical and functional outcomes. Methods: This post hoc analysis of a one‐year, multicentre, prospective, observational study included outpatients with schizophrenia who required a change in their antipsychotic medication because of a physician‐perceived risk of medication non‐adherence. Patients were matched 1 : 1 using an optimal algorithm with rank‐based Mahalanobis distances. All‐cause medication discontinuation was compared using the Klein and Moeschberger test for survival and hazard ratios (HR) with 95% confidence intervals (CI) were calculated using a Cox proportional hazards model, stratifying on matched pairs. Results: Forty patients who initiated a depot antipsychotic could be matched to patients who initiated an oral antipsychotic. Fewer depot‐treated patients discontinued their antipsychotic medication at least once compared with oral‐treated patients [20% (8/40) vs. 40% (16/40)]. Depot‐treated patients discontinued their medication later (Klein and Moeschberger test p = 0.025) and were less likely to discontinue their initial antipsychotic medication [HR = 0.33 (95% CI, 0.12–0.92), p = 0.033] than oral‐treated patients. There were few differences in resource use and no differences in clinical and functional outcomes between cohorts. Conclusion: In this matched‐cohort analysis, patients with schizophrenia who were considered to be non‐adherent with their prior oral antipsychotics were less likely to discontinue their medication for any cause if they were initiated on depot compared with oral antipsychotics.