Comparative cost-effectiveness of 11 oral antipsychotics for relapse prevention in schizophrenia within Singapore using effectiveness estimates from a network meta-analysis.

This study modelled the cost-effectiveness of 11 oral antipsychotics for relapse prevention among patients with remitted schizophrenia in Singapore. A network meta-analysis determined the relative efficacy and tolerability of 11 oral antipsychotics (amisulpride, aripiprazole, chlorpromazine, haloperidol, olanzapine, paliperidone, quetiapine, risperidone, sulpiride, trifluoperazine and ziprasidone). The clinical estimates were applied in a Markov model to estimate lifetime costs and quality-adjusted life-years gained. Quality-of-life data were obtained from published literature. Resource utilization and cost data were retrieved from local hospital databases. The annual direct cost of healthcare services for a patient experiencing a relapse episode was three-fold that of a patient not in relapse of schizophrenia. The most favourable pharmacological treatment for relapse prevention was olanzapine with an annual probability of relapse of 0.24 (0.13-0.38) with placebo as a reference of 0.75 (0.73-0.78). Olanzapine emerged as the dominant treatment with the highest quality-adjusted life-years gained and lowest lifetime costs. Ziprasidone, aripiprazole and paliperidone incurred higher lifetime costs compared with no treatment. Probability and cost of relapse were key drivers of cost-effectiveness in sensitivity analyses. The data can help prescribers in choosing appropriate treatment and payers in allocating resources for the clinical management of this serious psychiatric disorder.