OBJECTIVE: Young adults frequently report social smoking. This study examined the relationship between different social smoking definitions and the co-use of cigarettes and alcohol, tobacco-related attitudes, and quitting efforts. METHOD: Cross-sectional data were collected at bars using randomized time location sampling among young adults aged 21-26 in San Diego, California from 2010 to 2011 (73% response rate). Multivariable logistic regression examined if current smoking and quit attempts were associated with tobacco-related attitudes, and whether social smoking self-identification or behavior was associated with cigarette-and-alcohol co-use, tobacco-related attitudes, quit attempts, or quitline use. RESULTS: Among 537 current smokers, 80% self-identified and 49% behaved as social smokers. Social smoking self-identification was positively associated with cigarette-and-alcohol co-use, and quit attempts. Social smoking behavior was negatively associated with tobacco marketing receptivity, quit attempts, and quitline use. Tobacco-related attitudes were associated with smoking but did not generally differ by social smoking status. CONCLUSION: Identification and behavior as a social smoker have opposing associations with co-use of cigarettes and alcohol and quit attempts. Tobacco cessation programs for self-identified social smokers should address co-use. Interventions denormalizing the tobacco industry or emphasizing the health effects of temporary smoking and secondhand smoke may address smoking among young adult bar patrons regardless of social smoking status
