Background and Aims
Smoking prevalence among homeless adults is exceedingly high, and high rates of comorbid substance use are among the barriers to abstinence experienced by this group. The extent to which smoking cessation might engender an escalation in comorbid substance use could be a concern prohibiting treatment provision and engagement. This study examined whether smoking abstinence status was associated with alcohol and substance use at 26 weeks post-randomization among homeless smokers in a smoking cessation trial.

Design
The current study was a secondary analysis of randomized smoking cessation intervention trial data.

Setting
The parent study was conducted in the Minneapolis/St. Paul area of Minnesota, USA.

Participants
Participants were 427 homeless adult smokers interested in quitting smoking.

Measurements
Covariates collected at baseline included alcohol, cocaine, marijuana/hashish, heroin, and “any” drug use, age, sex, race/ethnicity, education, tobacco dependence, length of time homeless, and treatment group. Biochemically-verified smoking abstinence and self-reported alcohol and substance use were collected at 26 weeks post-randomization.

Findings
Smoking abstinence was associated with fewer drinking days (p=.03), fewer drinks consumed on drinking days (p=.01), and lower odds of heavy drinking (p=.05), but not with differences in the number of days of cocaine, marijuana/hashish, heroin, or any drug use.

Conclusions
In homeless smokers, achieving smoking abstinence may be associated with a reduction in alcohol consumption but appears not to be associated with a substantial change in other drug use.