Alcohol consumption and quitting smoking in the International Tobacco Control (ITC) Four Country Survey.

Although greater alcohol consumption has been associated with decreased odds of quitting smoking in prospective studies, the aspects of drinking most strongly associated with quitting have not been fully explored and examination of potential confounder variables has been limited. Further studies are needed to inform efforts to enhance smoking cessation among the substantial portion of smokers who drink alcohol. The present study examines: (a) drinking frequency, average weekly quantity of alcohol consumption, and frequency of heavy drinking as prospective predictors of quit smoking behaviors, (b) difference across countries in this prediction, and (c) third variables that might account for the association between alcohol consumption and quitting smoking. Data were drawn from the International Tobacco Control Four Country Survey, a prospective cohort study of smokers in Australia, Canada, the UK, and the US. A total of 4831 participants provided alcohol data at one study wave and were re-interviewed 1 year later. Individuals who drank heavily (4+/5+ drinks for women and men, respectively) more than once a week had significantly lower rates of quitting smoking than all other participants, in part due to the fact that a significantly lower proportion of those making a quit attempt remained quit for more than 1 month at follow-up. The role of frequent heavy drinking did not differ by country or sex and was not accounted for by demographics, smoking dependence, or attitudes regarding quitting smoking. Neither drinking frequency nor weekly quantity of consumption showed robust associations with quitting behaviors. Results indicate further study of interventions to address heavy drinking among smokers is warranted.