Smoking reduction in a population-based cohort

To describe the factors associated with smoking reduction in a population-based cohort study in Cornella de Llobregat (Barcelona, Spain).

We used data from the Cornella Health Interview Survey Follow-up Study (n = 2,500). We included for the analysis those subjects who declared to be daily smokers at baseline (1994) and continued smoking after eight years of follow-up (n = 234). We considered as operational definition of reduction to reduce > or = 10 cigarettes/day. We calculated the relative risk (RR) of smoking reduction vs. maintain or increase tobacco consumption and 95% confidence intervals (CI) by means of a Breslow-Cox regression model.

The average reduction on number of cigarettes among subjects who reduced their tobacco consumption was similar in men and women (13 cigarettes/day). The consumption intensity and self-perceived health are the characteristics associated with reduction: smoking reduction was associated with being a smoker > 20 cigarettes/day (RR = 3.25; 95% CI: 1.69-6.25) and individuals who declared having a suboptimal health showed a 3-fold risk of reducing smoking (RR = 3.13; 95% CI: 1.52-6.43).

Heavy smokers and smokers with poor health are those smokers more likely to reduce their tobacco consumption. Specific actions targeting them could lead to increase reduction and even smoking cessation.