PMH33 The Cost-Effectiveness of Paliperidone ER in Spain

Abstract

Paliperidone ER Extended Release OROS (ER) is a relatively new atypical antipsychotic for the treatment of schizophrenia. The objective is, based on a previously published model, to analyze the clinical and economic effects of Paliperidone ER in Spain compared to olanzapine oral and aripiprazole. An existing discrete event simulation model was adapted to reflect the treatment of schizophrenia in Spain in terms of costs, resource use and treatment patterns. Inputs for the model were derived from clinical trial data, literature search, database analysis, and interviews with local clinical experts. The time horizon is five years and Spanish discount rates were applied. Outputs included direct medical costs and Quality Adjusted Life-Years (QALYs). Sensitivity analyses were conducted to assess the uncertainty surrounding incremental outcomes and to identify model drivers, by performing probabilistic sensitivity analysis (PSA) and ordinary least squares analysis (OLSA). The mean (95% CI) incremental QALYs compared to olanzapine is 0.033 [-0.14, 0.30] and compared to aripiprazole 0.029 [-0.11,0.30]. The corresponding mean incremental costs (95% CI) are -€ 1,425 [-€ 10,247, €3,084] and -€ 759 [-€ 10,479, € 3,404] respectively. Based on the PSA, the probability that paliperidone ER is cost-saving and improves QALYs compared to olanzapine and aripiprazole is 76% and 72% respectively. Paliperidone ER was estimated to have 80% and 81% probability of being cost effective compared to olanzapine at a willingness to pay of €20,000 and €30,000 and 73% and 74% compared to aripiprazole respectively. OLSA identified drug acquisition costs, side effects and risk of relapse to be major model drivers. Based on differences in drug acquisition costs, side effects and risk of relapse, the model predicts that in Spain paliperidone ER provides QALY gains and cost savings compared with oral olanzapine and aripiprazole with a probability of 76% and 72% respectively.