Cost-effectiveness of 3-month paliperidone therapy for chronic schizophrenia in the Netherlands

Abstract

Background: A new depot formulation of paliperidone has been developed that provides effective treatment for schizophrenia for 3 months (PP3M). It has been tested in phase-3 trials, but no data on its cost-effectiveness have been published.Purpose: To determine the cost-effectiveness of PP3M compared with once-monthly paliperidone (PP1M), haloperidol long-acting therapy (HAL-LAT), risperidone microspheres (RIS-LAT), and oral olanzapine (oral-OLZ) for treating chronic schizophrenia in The Netherlands.Methods: A previous 1-year decision tree was adapted, based on local inputs supplemented with data from published literature. The primary analysis used DRG costs in 2016 euros from the insurer perspective, as derived from official lists. A micro-costing analysis was also conducted. For the costing scenario, official list prices were used. Clinical outcomes included relapses (treated as outpatients, requiring hospitalization, total), and quality-adjusted life-years (QALYs). Rates and utility scores were derived from the literature. Economic outcomes were the incremental cost/QALY-gained or relapse-avoided. Model robustness was examined in scenario, 1-way, and probability sensitivity analyses.Results: The expected cost was lowest with PP3M (8,781€), followed by PP1M (10,325€), HAL-LAT (11,278€), RIS-LAT (11,307€), and oral-OLZ (13,556€). PP3M had the fewest total relapses/patient (0.36, 0.94, 1.39, 1.21, and 1.70, respectively), hospitalizations (0.11, 0.46, 0.40, 0.56, and 0.57, respectively), emergency room visits (0.25, 0.48. 0.99, 0.65, and 1.14, respectively) and the most QALYs (0.847, 0.735, 0.709, 0.719, and 0.656, respectively). In both cost-effectiveness and cost-utility analyses, PP3M dominated all other drugs. Sensitivity analyses confirmed base case findings. In the costing analysis, total costs were, on average, 31.9% higher than DRGs.Conclusions: PP3M dominated all commonly used drugs. It is cost-effective for treating chronic schizophrenia in the Netherlands. Results were robust over a wide range of sensitivity analyses. For patients requiring a depot medication, such as those with adherence problems, PP3M appears to be a good alternative anti-psychotic treatment.