An economic assessment of quetiapine and haloperidol in patients with schizophrenia only partially responsive to conventional antipsychotics.

BACKGROUND Many patients with schizophrenia exhibit only a partial response to conventional antipsychotic agents, making them difficult to treat adequately. OBJECTIVE This analysis models the cost-effectiveness of quetiapine compared with haloperidol in partial responders with schizophrenia. METHODS Outcome data from the Partial Responders International schiZophrenia Evaluation (PRIZE) clinical trial comparing quetiapine and haloperidol in partial responders with schizophrenia as defined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition were combined with data from the literature to construct a Markov model. The model was used to calculate treatment outcomes and total direct treatment costs from the perspective of the United Kingdom National Health Service over 5 years. RESULTS The PRIZE study showed that quetiapine treatment resulted in a higher response rate and better tolerability than haloperidol treatment. These benefits have the potential to improve compliance and reduce relapse rates. The model showed that the higher acquisition cost of quetiapine was offset by lower costs for other medications, hospitalization, and other medical services. The total treatment cost over 5 years was 38,106 pounds for quetiapine and 38,350 pounds for haloperidol, a cost saving of 244 pounds in favor of quetiapine. Quetiapine-treated patients also spent longer in response states and experienced fewer relapses. Sensitivity analysis showed these results to be robust across a range of conditions. CONCLUSIONS Quetiapine has the potential to improve outcomes compared with haloperidol in partial responders with schizophrenia, at a slightly lower total cost. The higher acquisition cost of quetiapine was offset by savings in other medical costs. Quetiapine could significantly improve the management of this patient group, without increasing the economic burden on the health service.