While overall tobacco consumption is declining in many countries, patterns of low-frequency smoking - such as non-daily and low-rate daily smoking - appear to be increasing. We aimed firstly to describe differences in demographic, smoking- and quitting-related characteristics between non-daily 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.
We assessed a cohort of individuals born in Dunedin, New Zealand, in 1972-73, at regular intervals from age 21 to age 38 years. Smokers were categorised as either non-daily, low-rate daily (i.e. defined as 5 or less cigarettes per day) or high-rate daily smokers (6 or more cigarettes per day). Descriptive statistics, linear and logistic regression were used.
Non-daily smokers at age 21 tended to self-identify as non-smokers. Both non-daily smokers and low-rate daily smokers reported higher readiness and confidence in quitting compared to high-rate daily smokers. Around 33% of the age 21 low-rate daily smokers reported smoking daily at age 38, compared to 13% of the non-daily smokers and 4% of the non-smokers. Non-daily smoking at age 21 was associated with increased odds of being a daily smoker by age 38 (OR: 3.6; 95% CI: 1.7-7.8) compared to non-smokers.
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.