Objective. To evaluate the relationship between attention-deficit hyperactivity disorder (ADHD) and injuries and to verify whether methylphenidate (MPH), is associated with decreasing the risk of injuries.
Methods. A retrospective cohort study using the computerized database of Maccabi Healthcare Services. The ADHD cohort included all children between 12 and 20 years of age, newly diagnosed with ADHD between 2003 and 2013. The comparison cohort was composed of children who were not diagnosed with ADHD. The primary outcome was traumatic injuries. A Cox proportional hazard regression analysis was conducted to estimate ADHD effects on the risk of injuries. We also conducted a nested case-control study to examine how MPH influences this relationship.
Results. A total of 59 798 children were included in the cohort study; 28 921 were classified as exposed (ADHD cohort) and 30 877 were unexposed. The traumatic injuries incidence in the exposed group was significantly higher (adjusted hazard ratio = 1.63 [95% confidence interval = 1.60-1.66]). Similar increased risk was documented also for severe injuries (adjusted hazard ratio = 1.72 [1.59-1.86]). MPH use was significantly associated with 28% lower injury events. Therapy groups were significantly associated with 29% to 40% lower injuries rate for medium- or long-acting MPH. The intensity of therapy was significantly associated with 29% to 33% lower injury rate when the intensity was lower than 0.69 mg/kg/day.
Conclusion. Children with ADHD have a 60% increased odds of experiencing an injury. Treatment with MPH reduced the risk by up to 28%. The individual and financial cost secondary to injuries, underscores the public health significance of this problem. Injury prevention should be considered in clinical evaluation of MPH risks and benefits, beyond the conventional consideration of enhancing academic achievements.