To the Editor.
—Soumerai et al1 provide compelling evidence that in elderly survivors of AMI the underuse of β-blockers is associated with adverse clinical outcomes. Mortality rate among β-blocker recipients was 43% less than that for non-recipients after controlling for patient variables, indicators of severity of illness, and other indicators of comorbidities. Excluded from analysis were patients who had a contraindication to β-blocker use, including patients who used bronchodilators or had a diagnosis of asthma or chronic obstructive pulmonary disease.The authors indicated that a limitation of the study was their inability to measure lifestyle risk factors, such as smoking, that are not contained in administrative databases. They stated that "this limitation would not affect our results unless such factors are associated with β-blocker use."1 It seems plausible, even in the absence of clinical asthma or chronic obstructive pulmonary disease, that physicians may regard smoking as a relative contraindication to the
Jay SJ. Adverse Outcomes of Underuse of β-Blockers in Elderly Patients. JAMA. 1997;277(18):1434-1435. doi:10.1001/jama.1997.03540420030017