Summary

This large retrospective cohort study, using data from over one million children and young adults, did not show an association between current or former use of ADHD medication and serious cardiovascular events.

Design

• N=1,200,438 persons, ages 2-24 years, gathered from electronic health records from four health plans around the United States.
• Cohort had 373,667 person-years of current use of ADHD medication.
• Serious cardiovascular events identified, including sudden cardiac death, acute myocardial infarction, stroke.
• Cox regression models used to calculate hazard ratio for users of ADHD medications, compared with nonusers.
• The study excluded children with possibly life-threatening illness.

Results

• Serious cardiovascular events occurred at a rate of:
  • 7 events per 373,667 person-years for current users (1.9 events per 100,000 person-years).
  • 25 events per 607,475 person-years for former users (4.1 events per 100,000 person-years).
  • 49 events per 1,597,962 person-years for nonusers (3.1 events per 100,000 person-years).
• Current ADHD medication use was not associated with serious cardiovascular events: Adjusted hazard ratio = 0.75 (95% CI, 0.31-1.85).
• Prior ADHD medication use was also not associated with serious cardiovascular events: Adjusted hazard ratio = 1.03 (95% CI, 0.57-1.89).
• Considered by itself, methylphenidate, the most frequently used ADHD medication, was also not associated with serious cardiovascular events: Adjusted hazard ratio: 0.96 (95% CI, 0.31-2.97).
• The authors note that the low incidence of events limited the study’s statistical power, especially in regards to more rare events and more rarely-used medications.

Reference

Cooper WO, Habel LA, Sox CM, et al. ADHD drugs and serious cardiovascular events in children and young adults. N Engl J Med. 2011;365(20):1896-1904. doi:10.1056/NEJMoa1110212.