Long-term Outcomes of Early Use of Long-Acting Injectable Antipsychotics in Schizophrenia

Background: Long-acting injectable antipsychotics (LAIs) may potentially benefit patients requiring psychiatric hospitalization during the early stages of schizophrenia. However, few studies have compared the long-term effectiveness between patients who switched to LAIs and those who remained on oral antipsychotics (OAPs). Methods: Using the Taiwan National Health Insurance Research Database, we constructed a population-based cohort with 19,813 new OAP users with ICD-9-CM-defined schizophrenia who were hospitalized from 2002 to 2005. Within this cohort, 678 patients who switched to LAIs during their hospitalization were identified. The LAI group was matched to patients who remained on OAPs (n = 678). The LAI cohort was further subdivided for analysis into patients who switched to LAIs within 3 years of OAP initiation ("an early stage") and those who switched after 3 years ("a late stage"). Conditional Cox regressions and conditional negative binomial regressions were used to estimate the risk of death and the number of hospital visits between the two groups. Results: During the 13-year study period, 312 patients switched to LAIs within the first 3 years of OAP initiation. All- and naturalcause mortalities in these patients were significantly lower than in those who remained on OAPs. The hazard ratios (HRs) for all- and natural-cause mortalities were 0.49 (95% confidence interval [CI], 0.27-0.87) and 0.30 (95% CI, 0.15-0.60), respectively. No significant decrease associated with LAIs was observed in unnatural- cause mortality. Patients receiving LAIs had lower risks of rehospitalization (incidence rate ratio [IRR] = 0.56, 95% CI, 0.45-0.69), psychiatric hospitalization (IRR = 0.63, 95% CI, 0.50-0.81), and psychiatric emergency room visits (IRR = 0.58, 95% CI, 0.45-0.75) compared to patients who remained on OAPs. Use of LAIs in the late stage of treatment did not decrease the risk of relapse or mortality. Conclusions: Switching to LAIs during the first 3 years of treatment improved antipsychotic adherence, decreased relapses, and reduced long-term mortality. Our results provide evidence to support the benefits of early LAI treatment in schizophrenia.