To the Editor.
—Dr Goldhaber and colleagues have published a worthy study1 looking at risk factors associated with pulmonary embolism in women. It is certainly useful, though not surprising, to hear that it confirmed that obesity, cigarette smoking, and hypertension portend an increased risk for thromboembolic events. My comment, however, pertains to wording used in the closing sentence of the article's abstract, which states that not only are the above variables correlated with pulmonary embolism, but that control of these risk factors will decrease the risk of same. There is, in fact, no evidence in the study presented that control of obesity, smoking, or hypertension will reduce the risk of pulmonary embolism, only that there exists a positive association. In counseling patients about control of these adverse behaviors and conditions, clinicians tend to infer that risk factor modification will lead to reduction in the incidence of pulmonary embolism (as