Background:
Mexico has one of the most substantial burden of tobacco-related illnesses in the world where smoking causes more than 60000 deaths per year in the country. Examining smoking patterns for different birth cohorts would provide valuable insight into the impact of tobacco control policies.

Methods:
Using smoking data for adults (age>=20) from Encuesta Nacional de Salud (National Health Survey; 2000) and Encuesta Nacional de Salud y Nutricion (National Health and Nutrition Surveys: 2006, 2012, 2016), we evaluated smoking trends by gender through age-period-cohort models with restricted cubic splines. Specifically, temporal effects by age, period, and birth cohort (1905-1990) on the prevalence of ever and current smoking were estimated. In combination with these estimates, a methodology developed by the Cancer Intervention and Surveillance Modeling Network Lung group is used to reconstruct smoking histories by cohort and gender for Mexico population based on these cross-sectional surveys.

Results:
As expected, levels of ever and current smoking prevalence are higher for men compared to women. The prevalence of ever smokers has been decreasing in both sexes across all birth cohorts, with a sharper rate of decrease for women. Current smoking prevalence has also been declining in both sexes across all birth cohorts. The rates of decrease for current smoking differ between men and women, however; the prevalence of current smokers in men decreased at a faster rate for cohorts born before 1960 compared to women. Moreover, current smoking has been decreasing across all ages in both men and women.

Conclusions:
This is the first attempt to study smoking trends in Mexico using age-period-cohort models. The resulting estimates will help us reconstruct smoking histories, shedding light on patterns of smoking initiation and cessation in the population over time. Together, this information could inform tobacco control interventions to decrease the burden of tobacco-related illnesses in the country.