Risperidone Olanzapine Drug Outcomes studies in Schizophrenia (RODOS): health economic results of an international naturalistic study

We report the health economic data from the Risperidone Olanzapine Drug Out comes studies in Schizophrenia (RODOS) programme. Details of the efficacy a nd tolerability data from RODOS are available in a companion paper. The pop ulation analysed during RODOS consisted of 1901 patients with diagnoses of schizophrenia or schizoaffective disorder, The mean +/- SD daily dose of ol anzapine treatment was 14.5 +/- 5.1 mg compared to 5.3 +/- 2.6 mg for rispe ridone. Use of concomitant neuroleptics (risperidone, 65%; olanzapine, 62%; P = 0.2) and other concomitant drugs (risperidone, 76%; olanzapine, 73%; P = 0.2) was similar in both groups. The mean +/- SD total costs of all inpa tient drugs was significantly (P < 0.001) higher for olanzapine (US$297.5 /- 305.1) than risperidone (US$159.9 +/- 183.3). Although this difference i n the average total costs in part reflects the longer treatment duration fo r olanzapine compared to risperidone (34 days versus 31 days), the cost dif ference remained when looking at costs on a daily basis. The mean +/- SD da ily cost of all inpatient drugs was also significantly (P < 0.001) higher f or olanzapine (US$7.7 +/- 4.0) than for risperidone (US$4.6 +/- 2.9). These findings were very consistent across all nine countries. The results from RODOS suggest that treatment costs are significantly higher with olanzapine than with risperidone without any clinical benefit to offset this. (C) 200 1 Lippincott Williams & Wilkins.