Probabilistic Markov Model Estimating Cost Effectiveness of Methylphenidate Osmotic-Release Oral System Versus Immediate-Release Methylphenidate in Children and Adolescents: Which Information is Needed?

Background: Incidence of attention deficit hyperactivity disorder (ADHD) in children and adolescents has been increasing. The disorder results in high societal costs. Policymakers increasingly use health economic evaluations to inform decisions on competing treatments of ADHD. Yet, health economic evaluations of first-choice medication of ADHD in children and adolescents are scarce and gen- erally do not include broader societal effects. Objectives: This study presents a probabilistic model and analysis of methylphenidate osmotic-release oral system (OROS) versus methylphenidate immediate-release (IR). We investigate and include relevant societal aspects in the analysis so as to provide cost-effectiveness estimates based on a broad societal perspective. Methods: We enhanced an existing Markov model and determined the cost effectiveness of OROS versus IR for children and adolescents responding suboptimally to treatment with IR. Enhancements included screening of a broad literature base, updated utility values, inclusion of costs and effects on caregivers and a change of the model type from deterministic to probabilistic. Results: The base case scenario resulted in lower incre- mental costs (€-5815) of OROS compared with IR and higher incremental quality-adjusted life-year (QALY) gains (0.22). Scenario analyses were performed to deter- mine sensitivity to changes in transition rates, utility of caregivers, medical costs of caregivers and daily medica- tion dose. Conclusions: The results indicate that, for children re- sponding suboptimally to treatment with IR, the beneficial effect of OROS on compliance may be worth the additional costs of medication. The presented model adds to the health economic information available for policymakers and to considerations on a broader perspective in cost-ef- fectiveness analyses.