Gender modifies the relationship between social networks and smoking among adults in Seoul, South Korea

Objective: To evaluate the interaction of gender with social network mechanisms and smoking behaviors in Seoul, South Korea, where smoking is common among men but not women. Methods: During 2002, telephone surveys were completed with 500 adults drawn from a probability sample in Seoul. Respondents described their smoking status, smoking rate (number of cigarettes smoked per day) and social networks by assessing who discouraged or encouraged smoking (smoking support) or smoked (smoking models). Multivariable regressions were used for analyses. Results: Women encountered significantly less smoking support than men, 88% (95% confidence interval [95% CI], 85-91) versus 70% (95% CI 66-73) net discouragement of smoking in their network. A difference in smoking support from 25 to 75% net discouragement was associated with a 27% (95% CI 9-49) lower probability of smoking among women, significantly stronger (z = 3.18, p <0.01) than among men who had a 19% (95% CI 8-27) lower probability of smoking. A similar difference in smoking support was associated with male smokers smoking 6.38 (95% CI 0.86-12.30) fewer cigarettes per day, or 2,329 (95% CI 314-4,490) fewer cigarettes per year. The later association could not be observed among women due to the small proportion of female smokers. Smoking models were not significantly associated with any smoking behaviors across genders. Conclusions: Social network mechanisms were differentially associated with the high smoking prevalence among men and low prevalence among women and should be targeted by interventions tailored to these differences.