Trends and Demographic Differences in the Incidence and Mean Age of Starting to Smoke Cigarettes Regularly, National Health Interview Survey, 1997-2018

Objectives: Surveillance of cigarette smoking behavior provides evidence for evaluating the impact of current tobacco control measures. We examined temporal changes and demographic differences in the incidence and mean age of starting to smoke cigarettes regularly in the United States. Methods: We conducted retrospective birth-cohort and cross-sectional analyses using self-reported data from the 1997-2018 National Health Interview Survey to evaluate trends and demographic differences in the incidence and mean age of starting to smoke cigarettes regularly among participants aged 18-84 years. We estimated the incidence and mean age of starting to smoke cigarettes regularly by using Poisson and linear regression. Results: Among adults born during 1950-1999, the incidence of starting to smoke cigarettes regularly before age 35 years decreased by 18.8% (95% CI, 17.0%-20.7%) per 10 years, with a peak incidence at age about age 18 years. Male, non-Hispanic White, and US-born people had a higher incidence of starting to smoke cigarettes regularly than female, other racial and ethnic, and non-US-born people, respectively (P < .001 for all). From 1997 to 2018, the mean age of starting to smoke cigarettes regularly decreased by 0.4% (95% CI, 0.2%-0.6%) per 10 years among adults who ever smoked. Conclusion: The incidence of starting to smoke cigarettes regularly decreased dramatically at all ages during the study period, which suggests a positive impact of current tobacco control measures. For evaluating trends in starting to smoke cigarettes regularly, incidence can be a more sensitive indicator of temporal change than mean age. Differences in smoking incidence by demographic subgroup suggest that additional opportunities exist to further reduce the incidence of starting to smoke cigarettes regularly.