The study showed that women’s risk of death from smoking-related illnesses is now equivalent to that of men. The researchers also found that, while lung cancer risk leveled off in the 1980s for men, it is still rising for women. The researchers measured trends in mortality during three time periods – 1959–1965, 1982–1988, and 2000–2010 — after analyzing data from two historical cohort studies and in five pooled contemporary cohort studies, among participants who became 55 years of age or older during follow-up.
After analyzing cohort data, the researchers found the relative risk of female to male smokers versus nonsmokers. Relative risk expresses a ratio of the probability of the event occurring in the exposed group versus a non-exposed group, such as smokers versus nonsmokers. For example, the relative risk of women who smoke that get lung cancer would be: number of women who smoke have lung cancer/total number of women who smoke with or without lung cancer divided by the number of non-smoking women who have lung cancer/total number of nonsmoking women with or without lung cancer. For women who were current smokers, as compared with women who had never smoked, the relative risks of death from lung cancer were 2.73, 12.65, and 25.66 in the 1960s, 1980s, and contemporary cohorts. The corresponding relative risks for male current smokers were 12.22, 23.81, and 24.97. The women’s relative risk of death in the contemporary cohorts was higher than that of men.
The authors concluded that the relative risks of death from all causes — including lung cancer, COPD, ischemic heart disease, and any type of stroke — are almost identical for female and male smokers. For men 55 to 74 years of age and for women 60 to 74 years of age, the rate of death from all causes is