Antipsychotic treatment and risk of discontinuation and hospitalization in first-episode schizophrenia: a nationwide population-based study

Background Current evidence on antipsychotic treatment and risk of psychiatric hospitalization in first-episode schizophrenia (FES) is largely based on the findings from randomized clinical trials (RCTs). However, the generalization of the findings to real-world patients is limited due to inherent caveats of the RCT. We aimed to investigate the treatment discontinuation and risk of psychiatric hospitalization using a nationwide population database. Methods The Health Insurance Review Agency database in South Korea was obtained, and the observation period started from 1 January 2009 to 31 December 2016. We defined the maintenance period as the period from 6-month after the diagnosis of schizophrenia, which is utilized for the main results. For a total of 44 396 patients with FES, a within-individual Cox regression model was used to compare the risk of the treatment discontinuation and psychiatric hospitalization. Results In group comparison, a long-acting injectable (LAI) antipsychotic group was associated with the lowest risk of the treatment discontinuation (0.64, 0.55-0.75) and psychiatric hospitalization (0.29, 0.22-0.38) in comparison with a typical antipsychotic group and no use, respectively. Among individual antipsychotics, the lowest risk of the treatment discontinuation was observed in LAI paliperidone (0.46, 0.37-0.66) compared to olanzapine. Clozapine was found to be the most effective antipsychotic in lowering the risk of psychiatric hospitalization as monotherapy compared to no use (0.23, 0.18-0.31). Conclusions In real-world patients with FES, LAI paliperidone and clozapine were associated with low treatment discontinuation and better effectiveness in lowering the risk of psychiatric hospitalization.