Patient Characteristics and Treatment Discontinuation in a Taiwanese Cohort of the Intercontinental Schizophrenia Outpatient Health Outcomes (IC-SOHO) Study

Abstract

Objective: This report was to present the demographic and clinical outcomes of the Taiwanese cohort of the Intercontinental Schizophrenia Outpatient Health Outcomes (IC-SOHO) study for the readership of Taiwanese psychiatrists. Methods: The IC-SOHO was a three-year, naturalistic, prospective, observational study which was designed to compare outcomes of outpatients with schizophrenia who had initiated or changed antipsychotic medications. They were divided into olanzapine and other non-olanzapine antipsychotic groups. Evaluations included clinical severity, social functioning, health-related quality of life, and medication tolerability. Time to treatment discontinuation was analyzed using the Kaplan-Meier method. Results: A total of 300 patients was enrolled in this Taiwanese cohort, and 81.6% (245 patients) of them received initial antipsychotic monotherapy. Despite the absence of randomization in this study, no significant differences were found between the treatment cohorts in the socio-demographic and clinical characteristics at baseline of those two groups. The mean doses of treatments were increased in those two groups over the 36-month period and the uses of non-antipsychotic concomitant medications remained high throughout the study. Patients who remained at the end of the study showed a clinical response to treatment indicated by reductions in CGI-S scores in all domains, but these changes were not significantly different between those two groups. The estimated time to medication discontinuation for 50% of patients was 36.3 (95% CI 31.2, 38.4) months for those in the olanzapine group and 18.0 (95% CI 11.3, 30.1) months for patients receiving other monotherapy; the hazard ratio was 0.65 (95% CI 0.43, 0.99). But their weight gain was signifi cantly greater for the olanzapine group over the first 12 months of treatment. Conclusion: The results of this naturalistic, observational study offer an important description of the clinical characteristics and outcomes associated with the long-term use of antipsychotic treatment of schizophrenia in a cohort of Taiwanese patients.