Cost-effectiveness of guanfacine extended-release versus atomoxetine for the treatment of children and adolescents with attention-deficit/hyperactivity disorder in Canada


      Attention-deficit/hyperactivity disorder (ADHD) is a common childhood psychiatric disorder, with worldwide prevalence varying from 2.2 to 17.8%. Although stimulants are the recommended first-line treatment for ADHD, approximately 30% of children with ADHD do not have adequate response to the stimulants and may require alternative treatments to control their symptoms. Atomoxetine (ATX) and guanfacine extended-release (GXR) are once-daily, non-stimulants intended for the treatment of ADHD. The objective was to assess the cost-effectiveness of GXR compared to ATX in the treatment of children and adolescents with ADHD, from a Canadian perspective.


      A Markov model that included the following health states: treatment response, no response, and treatment discontinuation was developed. Transition probability from non-response to response during the titration period was estimated using the predicted treatment response rates estimated by a previously published matching-adjusted indirect comparison (MAIC); mean change in ADHD-RS-IV total score from baseline to endpoint was the efficacy outcome. The incidence rates of adverse events were based on those observed in the clinical trials included in the MAIC. Analyses were conducted from both a societal and a Canadian Ministry of Health (MoH) perspective over a 1-year time horizon with weekly cycles. Deterministic and probabilistic sensitivity analyses (PSA) were conducted to assess the robustness of the base-case results.


      Compared with ATX, GXR was a dominant strategy (lower cost and improved efficacy) from a societal perspective, while it was associated with an incremental cost-effectiveness ratio (ICER) of $57,866/QALY from a Canadian MoH perspective. Results of the PSA indicated that the ICER remains below the $50,000 willingness to pay threshold in 93.4% and 61.3% of the simulations from a societal and a Canadian MoH perspective, respectively.


      This analysis found that GXR was cost-effective relative to ATX in a majority of scenarios and perspectives in the treatment of children and adolescents with ADHD in Canada.