Sex differences in smoking cessation outcomes of a tailored program for individuals with substance use disorders and mental illness.

Tobacco use is highly prevalent among individuals with a history of substance use disorders (SUD) and/or mental illness (MI). Despite evidence of differences in smoking cessation (SC) outcomes between women and men, few studies have formally evaluated sex differences among SUD and/or MI populations. For 258 participants (62% male, mean age=48.6 years) with an SUD and/or MI enrolled in a tobacco dependence clinic (TDC) program, we examined SC outcomes and compared men's and women's predictors of end-of-treatment abstinence. Individuals with an MI, social support for quitting, and a greater number of visits to the TDC program were more likely to be female; whereas males were characterized by having an SUD, older age, smoking a greater number of cigarettes per day, and having higher confidence in quitting smoking. In the intent-to-treat analysis, end-of-treatment smoking cessation was 32.2% (females=35.4% vs males=30.2, χ(2)=0.74, df=1, p=.390). Among females, baseline expired carbon monoxide (CO) level and a greater number of visits to the program were significantly predictive of SC; among males, having a history of alcohol, heroin and other opioids, and marijuana use were predictive of unsuccessful SC, whereas baseline expired CO level and a greater number of visits to the program were predictive of SC. These factors may be important in the design of enhanced tailored treatments and development of future SC programs for individuals with SUD and MI.