Burden of male hardcore smokers and its characteristics among those eligible for lung cancer screening

There are few data available about hardcore smokers and their behavioral characteristics among the lung cancer screening (LCS) population. The study investigated the burden of hardcore smokers within the LCS population, and determine the characteristics of hardcore smokers using nationally representative data in South Korea.

We used data from 2007 to 2012 from the Korean National Health and Nutrition Examination Survey. This study enrolled current male smokers aged 55-74 years. Among them, subjects eligible for LCS were defined as these populations with smoking histories of at least 30 PY. Hardcore smoking was defined as smoking >15 cigarettes per day, with no plan to quit, and having made no attempt to quit. Multivariate logistic regression analyses were used to estimate associations between hardcore smokers and various sociodemographic and other variables.

The proportion of hardcore smokers among those who met LCS eligibility criteria decreased from 2007 to 2012 (from 39.07 to 29.47% of the population) but did not change significantly thereafter (P = 0.2770), and that proportion was consistently 10-15% higher than that of hardcore smokers among all male current smokers. The proportion without any plan to quit smoking decreased significantly from 54.35% in 2007 to 38.31% in 2012. However, the smokers who had made no intentional quit attempt in the prior year accounted for more than half of those eligible for LCS, and the proportion of such smokers did not change significantly during the study period (50.83% in 2007 and 51.03% in 2012). Multivariate logistic regression analyses showed that hardcore smokers were older (OR = 1.05, 95% confidence interval [CI] 1.01-1.09) than non-hardcore smokers. Hardcore smokers exhibited higher proportion of depression (OR = 6.55, 95% CI 1.75-24.61) and experienced extreme stress more frequently (OR = 1.93, 95% CI 1.13-3.29). Smokers who did not receive smoking cessation education within the past year were significantly more likely to be hardcore smokers (OR = 4.15, 95% CI 1.30-13.22).

It is important to identify a subset of smokers unwilling or minimally motivated to quit within the context of lung cancer screening. Anti-smoking education should be enhanced to influence hardcore smokers' behavior.