Risperidone olanzapine drug outcomes studies in schizophrenia (RODOS): efficacy and tolerability results of an international naturalistic study

Abstract

The Risperidone Olanzapine Drug Outcomes studies in Schizophrenia (RODOS) programme was an international series of naturalistic studies designed to evaluate drug use patterns and outcomes. RODOS consisted of retrospective chart reviews performed in patients who had been admitted to hospital and treated in 61 centres in nine countries. The analysed population consisted of 1901 patients with diagnoses of schizophrenia or schizoaffective disorder. The mean (SD) daily doses of risperidone and olanzapine were 5.3 (2.6) mg/day and 14.5 (5.1) mg/day, respectively. Patients treated with risperidone stayed an average of 3.8 days less in hospital compared to those receiving olanzapine (time to discharge was 43.6 days versus 47.4 days, respectively; P = 0.004). Risperidone was rated as effective in significantly more patients than olanzapine (84% versus 79%; P = 0.01). The time to onset of efficacy was significantly shorter with risperidone than with olanzapine (P < 0.001). The numbers of adverse events in the two treatment groups were not significantly different (13% risperidone, 11% olanzapine; P = 0.1). Correcting for small but statistically significant baseline differences between the two treatment groups did not produce a substantive change in the magnitude or significance of any outcome parameter. In conclusion, the clinical outcomes reported by RODOS suggest that risperidone may be more effective as a first-line therapy drug for schizophrenia than olanzapine.