Quitting smoking in northern Italy: a cross-sectional analysis of 2621 subjects.

To describe the relationship between sociodemographic factors, life-style habits, selected dietary indicators, smoking-related variables, and quitting smoking we analyzed data derived from the comparison group of a case-control study of colorectal and breast cancers based on a network of teaching and general hospitals in Northern Italy. A total of 2621 subjects (1215 women and 1406 men) who were ever cigarette smokers were included for analysis. Age-adjusted rates of stopping smoking (quit rates) and multivariate odds ratios (OR) of quitting smoking were computed. The overall age-adjusted quit rate was 38.6% for males and 24.9% for females, corresponding to an OR of quitting of 0.6 (95% CI: 0.5-0.7) for females vs males. The quitting rate increased with increasing age. After allowing for age, smoking cessation was more frequently reported by more educated or higher social class individuals. No relationship was present between quitting smoking and alcohol consumption, but quitting smoking was inversely related to coffee consumption. The probability of quitting smoking increased directly with number of cigarettes among males but not among females, who showed a J-shaped pattern. Older, heavy smokers were more likely to give up smoking. A general pattern of increasing rates of quitting smoking with higher consumption of vegetables and fruit, and hence beta-carotene, was present. This study confirms a positive association between quitting smoking and increasing age, higher education, low coffee consumption, heaviness of smoking and high consumption of vegetables and fruit.