Comparative Effectiveness of Antipsychotic Drugs for Rehospitalization in Schizophrenia-A Nationwide Study With 20-Year Follow-up

Very little is known about the comparative long-term effectiveness of novel antipsychotics in relapse prevention, especially in first-episode schizophrenia. Nationwide data from Finnish health care registers were gathered prospectively for all persons with periods of inpatient care due to schizophrenia in Finland during 1972-2014. Altogether 62 250 persons were included in the prevalent cohort, and 8719 in the incident (first-episode schizophrenia) cohort. The follow-up for antipsychotic use started at 1996 for the prevalent cohort, and at the first discharge from inpatient care for the incident cases. Within-individual Cox regression models for risk of psychiatric and all-cause hospitalization were constructed to compare risk during antipsychotic use and no use using individual as his/her own control to eliminate selection bias. With follow-up time up to 20 years (median = 14.1, interquartile range = 6.9-20.0), 59% of the prevalent cohort were readmitted to psychiatric inpatient care. Olanzapine long-acting injection (LAI; adjusted hazard ratio = 0.46, 95% confidence interval = 0.36-0.61), clozapine (0.51, 0.49-0.53), and paliperidone LAI (0.51, 0.40-0.66) were associated with the lowest risk of psychiatric rehospitalization in the prevalent cohort. Among first-episode patients, the lowest risks were observed for flupentixol LAI (0.24, 0.12-0.49), olanzapine LAI (0.26, 0.16-0.44), and perphenazine LAI (0.39, 0.31-0.50). Clozapine and LAIs were associated with the lowest risk of all-cause hospitalization in both cohorts. Clozapine and LAIs are the most effective treatments in preventing psychiatric and all-cause hospitalization among chronic and first-episode patients with schizophrenia.