RÉSUMÉ
OBJECTIVES: The aim of this analysis is to compare costs and effectiveness of paliperidone ER vs. placebo in the treatment of schizoaffective disorder (SAD) in the Czech Republic based on pooled clinical trial data. METHODS: A de novo micro-simulation model was developed to assess the cost-utility analysis of paliperidone vs. placebo as there is lack of clinical data comparing paliperidone to other interventions. There are no studies primarily evaluating the efficacy of treatment of SAD with other antipsychotics. The model estimated effectiveness and costs of patients with SAD every week during 24-week time horizon. The effectiveness was defined as improvement of a patient's PANSS score where utilities were assigned to each modelled PANSS score. Based on the patient level data a linear mixed-effects model was used to estimate the regression equations of percentage decrease of PANSS score from the baseline. Utilities were computed using a regression function of patients' age, sex and PANSS score, which was adapted from a clinical study of patients with schizophrenia as there are no QoL data on SAD patients. Among relevant costs, reflecting the payer's perspective, costs of pharmacotherapy, concomitant medications and outpatient care were considered. RESULTS: The average ICER of paliperidone compared to placebo reached 28,935 EUR/QALY. The probability of paliperidone being cost-effective compared to placebo was 99.5%. CONCLUSIONS: Treatment of SAD with paliperidone results in acceptable ICER and high probability of being cost-effective compared to placebo. Thus, it can be considered as a cost-effective treatment of patients with SAD in the Czech Republic.