Author Affiliations: Georgia Poison Center, Atlanta (email@example.com).
To the Editor: We have several questions about the investigation by Dr Habel and colleagues1 regarding the cardiovascular risks of medications for attention-deficit/hyperactivity disorder (ADHD) in young and middle-aged adults.
The authors used prescription records as a surrogate for exposure. This is an accepted practice in many epidemiological studies. However, in the United States, 16% to 29% of ADHD medication prescriptions are diverted, and up to 68% of young adult ADHD medication users report receiving the drugs from peers instead of physicians.2 Do the authors consider the stimulant diversion problem a significant confounder?
Devlin JJ, Punja M, Kazzi ZN. Cardiovascular Events in Adults Taking Medications for ADHD. JAMA. 2012;307(14):1485–1486. doi:10.1001/jama.2012.448