To the Editor.
—The publication of the article by Dr Psaty and colleagues1 on the potential risk of calcium antagonists seems unlikely to end the storm of controversy it has generated.2Communicating information this controversial is obviously complicated; however, we feel that not all the burden of blame can be passed off to the media. While sounding an appropriate note of caution, the accompanying Editorial3 missed an opportunity to bring balance to this controversy. On the technical side, while the potential for bias is a fundamental limitation of case-control studies, the concerns voiced in relation to this study were unconvincing. As the Editorial suggests, the issue of confounding by indication is obviously crucial; however, the specific form it was thought to take is not clear since patients with preexisting cardiovascular disease were excluded from the analysis. Would physicians have really treated patients for heart disease and not
Cooper RS, Freeman V. Myocardial Infarction Associated With Antihypertensive Drug Therapy. JAMA. 1996;275(7):515-516. doi:10.1001/jama.1996.03530310021014