Effectiveness of antipsychotic maintenance therapy with quetiapine in comparison with risperidone and olanzapine in routine schizophrenia treatment: results of a prospective observational trial

Objective of this observational trial is to examine the effects of quetiapine in comparison with olanzapine and risperidone on clinical outcomes and quality of life in patients with schizophrenia and schizoaffective disorder in routine care. 374 adult persons with schizophrenia or schizoaffective disorder prescribed antipsychotic maintenance therapy with quetiapine, olanzapine, or risperidone at discharge from inpatient treatment were included. Clinical and psychosocial outcomes were assessed before discharge and at 6, 12, 18, and 24 months. Statistical analyses were conducted by mixed-effects regression models for longitudinal data. The propensity score method was used to control for selection bias. Patients discharged on olanzapine had significantly lower hospital readmissions than those receiving quetiapine or risperidone. The average chlorpromazine equivalent dose of quetiapine was higher than in patients treated with olanzapine or risperidone. No further significant differences between treatment groups were found. Quetiapine and risperidone are less effective in preventing the need for psychiatric inpatient care than olanzapine, and higher chlorpromazine equivalent doses of quetiapine are needed to obtain clinical effects similar to those of olanzapine and risperidone.