A modelled economic evaluation comparing atomoxetine with methylphenidate in the treatment of children with attention-deficit/hyperactivity disorder in Spain

Abstract

Background: Attention Deficit/Hyperactivity Disorder (ADHD) is a neurobehavioural disorder, affecting 3-6% of school age children and adolescents in Spain. Methylphenidate (MPH), a mild stimulant, had long been the only approved medication available for ADHD children in Spain. Atomoxetine is a non-stimulant alternative in the treatment of ADHD with once-a-day oral dosing. This study aims to estimate the cost-effectiveness of atomoxetine compared to MPH. In addition, atomoxetine is compared to 'no medication' for patient populations who are ineligible for MPH (i.e. having stimulant-failure experience or co-morbidities precluding stimulant medication).

Methods: An economic model with Markov processes was developed to estimate the costs and benefits of atomoxetine versus either MPH or 'no medication'. The incremental cost per quality-adjusted life-year (QALY) was calculated for atomoxetine relative to the comparators. The Markov process incorporated 14 health states, representing a range of outcomes associated with treatment options. Utility values were obtained from the utility valuation survey of 83 parents of children with ADHD. The clinical data were based on a thorough review of controlled clinical trials and other clinical literature, and validated by international experts. Costs and outcomes were estimated using Monte Carlo simulation over a 1-year duration, with costs estimated from the perspective of the National Health Service in Spain.

Results: For stimulant-naive patients without contra-indications to stimulants, the incremental costs per QALY gained for atomoxetine were euro 34,308 (compared to an immediate-release MPH) and euro 24,310 (compared to an extended-release MPH). For those patients who have stimulant-failure experience or contra-indications to stimulants, the incremental costs per QALY gained of atomoxetine compared to 'no medication' were euro 23,820 and euro 23,323, respectively.

Conclusion: The economic evaluation showed that atomoxetine is an effective alternative across a range of ADHD populations and offers value-for money in the treatment of ADHD.

Figure 1

Structure of the Markov process in population 1. Abbreviation: ATX = atomoxetine; MPH = methylphenidate; NOTX = no medication; R = response; NR = no response; AE = adverse events; NOAE = no adverse events. ^a Either IR-MPH or XR-MPH is separately compared to atomoxetine. *Note: The Markov model is similarly structured even when atomoxetine is compared to 'no medication' for those who are ineligible for MPH treatment. In this case, all health states related to MPH are eliminated from the current model.

Figure 2

The ICERs of atomoxetine under varying utility values used in the model in population 1. Abbreviations: IR-MPH = immediate-release methylphenidate; XR-MPH = extended-release methylphenidate; QALY = Quality of life years.