PMH27: COST-UTILITY ANALYSIS OF QUETIAPINE COMPARED TO RISPERIDONE IN THE TREATMENT OF PATIENTS WITH SCHIZOPHRENIA OR OTHER PSYCHOTIC DISORDERS

Abstract

OBJECTIVE: Comparative cost-effectiveness was assessed in an open-label, randomized trial (QUEST) that compared the efficacy and safety of quetiapine with risperidone in a outpatient population with schizophrenia or other psychotic disorders. METHOD: Based on the overall Positive And Negative Syndrome Scale (PANSS) scores, patients in QUEST were categorized into one of three health states?mild (PANSS 74.5), moderate (PANSS> 74.5 and 106.5), or severe (PANSS score> 106.5)?at baseline and at 2 months and 4 months. Utilities and expected utilities from baseline were calculated. RESULTS: At baseline, 297 (54.0%), 206 (37.5%), and 47 (8.5%) quetiapine patients, had mild, moderate or severe symptoms compared to 102 (59.0%), 55 (31.8%), and 16 (9.2%) in the risperidone group. For patients in the mild or moderate states at baseline, improvements were seen in both treatment groups. For severe patients, more quetiapine patients improved: 21.2% versus 7.7% in the mild state and 60.6% versus 30.8% in the moderate state (p = 0.020) at 2 months and 46.9% versus 0.0% in the mild state and 40.6% versus 62.5% in the moderate state (p = 0.023) at 4 months. Overall, when weighted by utilities, quetiapine treated patients attained greater gains in health state utilities at each follow-up visit for the mild (0.61 ± 0.069), moderate (0.36 ± 0.073) and severe (0.29 ± 0.071) states. At 2-months, quetiapine patients enjoyed a gain of 0.239 from their baseline level compared to 0.175 for the risperidone group. At 4-months, the gains were 0.329 versus 0.184 for the quetiapine and risperidone groups (p < 0.05). Average daily doses were 253.9mg quetiapine and 4.4mg risperidone, yielding average daily costs to US consumers of $6.38 and $7.85. At average retail costs to consumers in the US, quetiapine reduces costs by $1.47/day or $536.55 annually. CONCLUSION: Patients with schizophrenia or other psychotic disorders, treatment with quetiapine resulted in significant effectiveness and cost savings compared with risperidone.