The impact of environmental tobacco smoke on women's risk of dying from heart disease: a meta-analysis

Abstract

Objective: To review systematically and analyze the association between environmental tobacco smoke (ETS) exposure and the risk of dying from heart disease in women.

Methods: We searched the English-language literature using MEDLINE (1966-April 2004), CINAHL, PsychInfo, and bibliographies of selected studies. We included studies that specifically addressed the association of ETS and heart disease mortality in women and had adequate controls and retrievable risk estimates. We looked for either cohort studies or randomized controlled trials. Studies were evaluated independently by two of the authors. Nine cohort studies were finally selected for analysis. We estimated the summary relative risk (RR) and associated 95% confidence intervals (95% CI) using a random-effects model.

Results: Mean follow-up periods for these cohorts ranged from 6 to 39 years. Among non-smoking women, exposure to ETS was associated with a 15% increase in the risk of dying from heart disease compared with nonsmoking women not exposed to ETS (RR = 1.15, 95% CI 1.03-1.28, p < 0.05).

Conclusions: Among nonsmoking women, exposure to passive smoke increases the risk of dying from heart disease. In accordance with the newly developed guidelines by the American Heart Association for prevention of cardiovascular disease (CVD) in women, we recommend counseling women on reducing or avoiding ETS exposure.