• Smoking-caused disease

In their article, Jamrozik et al (see page 258) have explored the mortality hazard associated with smoking by gender and provide evidence that Australian men and women with similar smoking histories (namely, cigarettes smoked per day and time since quit) experience similar rates of death from smoking.1 Given the limitations of the data in this study, caution should be used in interpreting these results. In fact, results from studies conducted across the globe provide conflicting evidence as to whether gender influences tobacco-related mortality patterns. More specifically, Freedman et al found, using a prospective cohort, that men in the USA have slightly higher incidence rates of lung cancer than women with similar smoking histories.2 A case–control study concluded that women have increased risk for developing lung cancer than men across all levels of cigarette use.3 On the other hand, in two other prospective US cohorts, findings indicate that overall risk did not differ by gender.4 5 The effect of gender on chronic obstructive pulmonary disease is also controversial, with studies showing conflicting results.6

These studies may reflect the complex history of smoking-related gender differences in the USA. Women who smoke have …