Background: Social impacts on tobacco use have been reported but not well quantified. This study investigated how strongly the use of smoked and smokeless tobacco may be influenced by other users who are close to the respondents.
Methods: The International Tobacco Control Project (TCP), India, used stratified multistage cluster sampling to survey individuals aged ≥15 years in four areas of India about their tobacco use and that of their close associates. The present study used logistic regression to calculate odds ratios (ORs) for tobacco use for each type of close associate.
Results: Among the 9780 respondents, tobacco use was significantly associated with their close associates' (father's, mother's, friends', spouse's) tobacco use in the same form. After adjusting for confounding variables, women smokers were nine times more likely to have a mother who ever smoked (OR: 9.0; 95% confidence interval [CI]: 3.3-24.7) and men smokers five times more likely (OR: 5.4; 95% CI: 2.1-14.1) than non-smokers. Men smokers were seven times more likely to have close friends who smoked (OR: 7.2; 95% CI: 5.6-9.3). Users of smokeless tobacco (SLT) were five times more likely to have friends who used SLT (OR: 5.3; 95% CI: 4.4-6.3 [men]; OR: 5.0; 95% CI: 4.3-5.9 [women]) and four times more likely to have a spouse who used SLT (OR: 4.1; 95% CI: 3.0-5.8 [men]; OR: 4.3; 95% CI: 3.6-5.3 [women]), than non-users. The ORs for the association of the individuals' tobacco use, whether smoked or smokeless, increased with the number of close friends using it in the same form.
Conclusion: The influence of family members and friends on tobacco use needs to be appropriately addressed in tobacco-control interventions.