Lifetime smoking habits among Norwegian men and women born between 1890 and 1994: a cohort analysis using cross-sectional data.

Objectives: Providing lifetime smoking prevalence data and gender-specific cigarette consumption data for use in epidemiological studies of tobacco-induced cancer in Norway. Characterising smoking patterns in birth cohorts is essential for evaluating the impact of tobacco control interventions and predicting smoking-related mortality.

Setting: Norway.

Participants: Previously analysed annual surveys of smoking habits from 1954 to 1992, and individual lifetime smoking histories collected in 1965 from a sample of people born in 1893-1927, were supplemented with new annual surveys of smoking habits from 1993 to 2013. Age range 15-74 years.

Primary Outcome Measure: Current smoking proportions in 5-year gender-and-birth cohorts of people born between 1890 and 1994.

Results: The proportion of smokers increased in male cohorts until the 1950s, when the highest proportion of male smokers (76-78%) was observed among those born in 1915-1934. Among women, the peak (52%) occurred 20 years later, in women born in 1940-1949. After 1970 smoking has declined in all cohorts of men and women. In the 1890-1894 cohorts, male smoking prevalence was several times higher than female, but the gap declined until no gender difference was present among those born after 1950. Gender-specific per capita consumption was even more skewed, and men have consumed over 70% of all cigarettes since 1930. The incidence of lung cancer for men peaked at around 2000, with the highest incidence rate estimated at ca. 38%. The incidence of lung cancer for women is still increasing, and estimated incidence rate for 2011 was 25.2%.

Conclusions: In an epidemiological perspective, men have had a longer and more intense exposure to cigarettes than women. The gender-specific incidence of lung cancer reflects the gender difference in consumption over time.