Psychostimulants/Atomoxetine and Serious Cardiovascular Events in Children with ADHD or Autism Spectrum Disorder

BACKGROUND: Psychostimulants and atomoxetine have been shown to increase blood pressure, heart rate, and QT interval in children and adolescents; however, based on current literature, it is unclear if these "attention-deficit/hyperactivity disorder (ADHD) medications" are also associated with serious cardiovascular (SCV) events. We addressed this question in commonly exposed groups of children and adolescents with either ADHD or autism spectrum disorder (ASD).METHODS: Using commercial (years 2000-2016) and Medicaid (years 2012-2016) administrative claims data from the United States (US), we conducted two case-control studies, nested within respective cohorts of ADHD and ASD children aged 3-18 years. We defined cases by a composite outcome of stroke, myocardial infarction, or serious cardiac arrhythmia. For each case, we matched ten controls on age, sex, and insurance type. We conducted conditional logistic regression models to test associations between SCV outcomes and a primary exposure definition of current ADHD medication use. Additionally, we controlled for resource use, cardiovascular and psychiatric comorbidities, and use of medications in a variety of sensitivity analyses.RESULTS: We identified 2,240,774 children for the ADHD cohort and 326,221 children for the ASD cohort. For ADHD, 33.9% of cases (63 of 186) versus 32.2% of controls (598 of 1860) were exposed, which yielded an odds ratio (OR) and 95% confidence interval (CI) of 1.08 (0.78-1.49). For ASD, 12.5% of cases (6 of 48) versus 22.1% of controls (106 of 480) were exposed [OR 0.49 (0.20-1.20)]. Covariate-adjusted results and results for individual outcomes and other exposure definitions were consistent with no increased risk of SCV events.CONCLUSION: Using large US claims data, we found no evidence of increased SCV risk in children and adolescents with ADHD or ASD exposed to ADHD medications.