Nondaily, Low-Rate Daily, and High-Rate Daily Smoking in Young Adults: A 17-Year Follow-Up

Introduction: While overall tobacco consumption is declining in many countries, patterns of lowfrequency smoking-such as nondaily and low-rate daily smoking-appear to be increasing. We aimed firstly to describe differences in demographic, smoking- and quitting-related characteristics between nondaily and daily smokers in young adults; secondly, to determine the proportion of low-frequency smokers who transition to a higher rate of smoking by age 38 and factors associated with this. Methods: We assessed a cohort of individuals born in Dunedin, New Zealand, in 1972-1973, at regular intervals from age 21 to age 38 years. Smokers were categorized as either nondaily, lowrate daily (ie, defined as five or less cigarettes per day) or high-rate daily smokers (six or more cigarettes per day). Descriptive statistics, linear and logistic regression were used. Results: Nondaily smokers at age 21 tended to self-identify as nonsmokers. Both nondaily smokers and low-rate daily smokers reported higher readiness and confidence in quitting compared to high-rate daily smokers. Around 40% of the age 21 low-rate daily smokers reported smoking daily at age 38, compared to 13% of the nondaily smokers and 4% of the nonsmokers. Nondaily smoking at age 21 was associated with increased odds of being a daily smoker by age 38 (OR: 3.6; 95% CI = 1.7% to 7.8%) compared to nonsmokers. Conclusions: Different patterns of smoking are associated with differences in readiness to quit and confidence in quitting ability. For a considerable proportion of smokers, low-frequency smoking in young adulthood develops into daily smoking by adulthood. Implications: Low-frequency smoking, including nondaily smoking, in early adulthood is a significant risk factor for being a daily smoker in the long-term. Cessation interventions should be tailored to low-frequency smokers, taking into account differences between them and heavier smokers in terms of smoking motivation and quitting-related cognitions.