Paper does not provide any reassurance

EDITOR—Shakir et al investigated the possibility of myocardial infarction being an adverse drug reaction among users of sildenafil.1 However, their paper suffers from the problem that users of the drug are not representative of the general male population.

The authors point out that the proportion of men with diabetes among the users of sildenafil was four to five times higher than the national average. The overall mortality from acute myocardial infarction is four times higher among diabetic than non-diabetic men.2 Thus standardisation by the general male population of England is not appropriate and will give an underestimate of the expected number of deaths in this cohort. The standardised mortality ratio should be even less than the 69.9% quoted. Are we to believe …