Remission and relapse in the outpatient care of schizophrenia: Three-year results from the schizophrenia outpatient health outcomes study

Remission and relapse are clinical outcomes of increasing interest in schizophrenia. We analyzed remission and relapse, and the sociodemographic and clinical factors associated with these outcomes, in the usual care of schizophrenia using the 3-year, follow-up data from a large cohort of outpatients with schizophrenia taking part in the prospective, observational, European Schizophrenia Outpatient Health Outcomes study. Of the 6516 patients analyzed for remission, 4206 (64.6%) achieved remission during the 3-year, follow-up period. Logistic regression analysis revealed that being female, having a good level of social functioning at study entry, and a shorter duration of illness were factors significantly associated with achieving remission. Treatment with olanzapine was also associated with a higher frequency of remission compared with other antipsychotic agents. A Kaplan-Meier survival curve estimated that relapse occurred in approximately 25% of the patients who achieved remission, with the risk of relapse remaining constant during the follow-up period. Shorter duration of illness, having hostile behaviors, and substance abuse were factors associated with a higher risk of relapse, whereas good level of social functioning and the use of olanzapine and clozapine were associated with a lower risk of relapse. In conclusion, the 3-year results of the Schizophrenia Outpatient Health Outcomes study indicate that the likelihood of remission decreases over the longitudinal course of schizophrenia, but risk of relapse is maintained even after 3 years of achieving remission severity levels. Results suggest that treatment with olanzapine is associated with a better chance of achieving remission than other antipsychotics. Moreover, the use of olanzapine and clozapine is associated with a lower risk of relapse compared with risperidone, quetiapine, and typical antipsychotics. The results should be interpreted conservatively because of the observational, nonrandomized study design.