Purpose: This study was designed to explore the preferences of parents of children with attention deficit hyperactivity disorder (ADHD) regarding oral and transdermal therapy; and also to characterise the parents with a stated preference for the transdermal therapy.
Method: A literature review and in depth interviews with parents and physicians helped identify the salient attributes of MPH therapy. A stated preference discrete choice experiment was developed. The survey presented 18 pairs of hypothetical treatments which varied by mode of administration (tablet, methylphenidate transdermal delivery system or MTS), speed of onset of effect (30, 60 or 90 minutes); duration of effect (lasts until 3pm, 6pm, 9pm) and ability to tailor the drug to different day to day needs (no flexibility, limited flexibility, easy to adjust to different days). Choice sets were determined using an orthogonal fold over design. Data were analysed using the repeated measurements Generalised Estimating Equations (GEE) model with binomial distribution and a logit link.
Result: Participants (N=200) overall expressed a significant preference for once a day oral therapy (Odds Ratio OR= 1.76 95%CI=1.43-2.18); with a rapid speed of onset (OR =1.22, 95%CI=1.07-1.39), symptom control lasting until 9pm (OR=3.79 95%CI=2.98-4.82) and with no flexibility in terms of variation in the duration of symptom control (OR=1.20 95%CI=1.07-1.35). However 33% of parents stated they preferred the MTS to oral treatment and further analyses revealed that these parents also had a preference for treatments with a longer duration of benefit and fast onset of action.
Conclusion: Analyses of these survey data reveal interesting heterogeneity in parents preferences for ADHD treatments. A distinct sub group of approximately one third of parents prefer the MTS to oral therapy. These people were less likely to be working fulltime and were more receptive to tailoring the treatment each day (compared with those who preferred oral therapy). These analyses are informative regarding the types of parents who prefer oral or MTS therapy acknowledging preference may impact persistence on treatment.
Candidate for the Lee B. Lusted Student Prize Competition