Comparative Effectiveness of Antipsychotics in Preventing Readmission for First-Admission Schizophrenia Patients in National Cohorts From 2001 to 2017 in Taiwan

Background and Hypothesis Antipsychotics remain the main treatment for schizophrenia, but their effectiveness is challenging to compare. We aimed to assess the comparative real-world effectiveness of antipsychotics in preventing readmission among patients in Asia with early-stage schizophrenia to inform clinical decision making. Study Design We did a retrospective cohort study of first-admission schizophrenia patients (ICD-9-CM: 295; ICD-10-CM: F20 and F25) from January 1, 2001, to December 31, 2017. The cohort was identified from the National Health Insurance Research Database NHIRD for Psychiatric Inpatients. The exposure was any antipsychotics prescribed post-discharge. The primary outcome was the readmission risk due to psychotic disorders, which was measured by adjusted hazard ratios (aHRs). Within-individual extended Cox models were applied for analyses, where the periods of oral risperidone use served as his or her own control. Study Results We selected 75 986 patients (men, 53.4%; mean [SD] age, 37.6 [12.0] years; mean [SD] duration of follow-up, 8.9 [5.0]) who were first admitted to psychiatric wards with schizophrenia in Taiwan. Among them, 47 150 patients (62.05%) had at least one readmission within 4 years. Compared to the period under treatment with oral risperidone, that under monotherapy with long-acting injectable antipsychotics (LAIs) had the lowest risk for psychotic readmission, with a risk reduction of 15-20%. However, the prevalence of person-prescription prevalence of LAIs remained low (< 10%) during the follow-up period. Conclusions The use of LAIs after the first admission for schizophrenia has notable advantages in preventing readmission. Such formulations should be offered earlier in the course of illness.