Methylphenidate and the risk of burn injury among children with attention-deficit/hyperactivity disorder

Abstract

Aims: Attention-deficit/hyperactivity disorder (ADHD) is associated with a higher risk of burn injury than in the normal population. Nevertheless, the influence of methylphenidate (MPH) on the risk of burn injury remains unclear. This retrospective cohort study analysed the effect of MPH on the risk of burn injury in children with ADHD.

Method: Data were from Taiwan's National Health Insurance Research Database (NHIRD). The sample comprised individuals younger than 18 years with a diagnosis of ADHD (n = 90 634) in Taiwan's NHIRD between January 1996 and December 2013. We examined the cumulative effect of MPH on burn injury risk using Cox proportional hazards models. We conducted a sensitivity analysis for immortal time bias using a time-dependent Cox model and within-patient comparisons using the self-controlled case series model.

Results: Children with ADHD taking MPH had a reduced risk of burn injury, with a cumulative duration of treatment dose-related effect, compared with those not taking MPH. Compared with children with ADHD not taking MPH, the adjusted hazard ratio for burn injury was 0.70 in children taking MPH for <90 days (95% confidence interval (CI) 0.64-0.77) and 0.43 in children taking MPH for ≥90 days (95% CI 0.40-0.47), with a 50.8% preventable fraction. The negative association of MPH was replicated in age-stratified analysis using time-dependent Cox regression and self-controlled case series models.

Conclusion: This study showed that MPH treatment was associated with a lower risk of burn injury in a cumulative duration of treatment dose-related effect manner.

Keywords: Attention-deficit/hyperactivity disorder; burn injury; methylphenidate.

Fig. 1.

Overview of the self-controlled case series study design. The self-controlled case series study design was used in this study for within-patient comparisons to examine the effect of methylphenidate on traumatic brain injury in adolescent patients with ADHD. The effect period for methylphenidate is set at 1–3 months. Thus, the effect period was split into three 1-month effect periods: 0–30, 31–60 and 61–90 days at the end of each treatment period. Individual's time not within the treatment period would serve as a self-controlled period for self-comparison. Time point of cohort entry was defined as the date of age of onset of ADHD. The end of follow-up was 31 December 2013.