To the Editor Given recent warnings by the US Food and Drug Administration and Health Canada about the potential cardiovascular risk of testosterone administration, the effects of testosterone are of intense interest. Layton et al1 add to the ongoing conversation by using medical records to show higher rates of cardiovascular events in men using testosterone injections than in men using testosterone gels. Understandably, given the difficulties of comparing testosterone users with nonusers in an observational study exploiting administrative data, Layton et al have not yet provided the other key comparison listed in the abstract of the National Institutes of Health grant that funded their work, and that is “to compare rates of cardiovascular events in testosterone users to those of non-users with comparable testosterone levels.”2 Without this key comparison, the findings by Layton et al are difficult to interpret, because neither the cardiovascular risk nor the benefit of testosterone use is given for any dosage form.
Schooling CM. Misinterpretation of the Comparative Safety of Testosterone Dosage Forms. JAMA Intern Med. 2015;175(11):1874-1875. doi:10.1001/jamainternmed.2015.5804