Results Participant Characteristics Participant characteristics are displayed in Table 1. Negative binomial regression analyses indicated that whereas the decrease in alcohol use from pretreatment to postcessation was statistically significant (B = ?.23, p = .01), the decline in inhibitor Pfizer marijuana use during this time period was not (B = ?.17, p = .25). Table 1. Participant Characteristics Attrition Attrition rates were low through Week 52 (Week 52 attrition rate = 18.8%). Pretreatment (B = ?.04, p = .009) and postcessation (B = ?.08, p = .0003) drinking quantity were both associated with a lower likelihood of missing outcome data across assessment periods. However, for both of these variables, missing participants were no more likely to be smoking than nonmissing participants.

Marijuana use was unrelated to attrition. These findings are consistent with the assumption that outcome data were missing completely at random (see Schneider, Hedeker, Bailey, Cook, & Spring, 2010). Relationships of Alcohol Use to Participant Characteristics Pretreatment drinking quantity was positively associated with cocaine use (r = .15, p = .001) and negatively associated with tobacco dependence (r = ?.09, p = .01). Thus, cocaine use and tobacco dependence were added as covariates in the model predicting smoking abstinence from pretreatment drinking quantity, and the mediational paths of pretreatment drinking quantity on smoking abstinence through smoking urge were adjusted for the influence of these variables. Postcessation drinking quantity was greater among men than women (mean difference = 1.

30, p = .01), positively associated with cocaine use (r = .20, p < .001), and negatively associated with age (r = ?.12, p = .001), years smoked tobacco (r = ?.11, p = .002), and tobacco dependence (r = ?.10, p = .006). Gender, cocaine use, age, years smoked tobacco, and tobacco dependence were therefore added as covariates in the model predicting smoking abstinence from postcessation Anacetrapib drinking quantity, and the mediational paths of postcessation drinking quantity on smoking abstinence through urge to smoke were adjusted for the effect of these constructs. Relationship of Alcohol Use to Smoking Abstinence Results of the GEE model predicting smoking abstinence from pretreatment alcohol use and its covariates are presented in Table 2, and results of the model predicting smoking abstinence from postcessation alcohol use and its covariates are displayed in Table 3. As seen in the tables, pretreatment and postcessation drinking quantity were both independently associated with a decreased likelihood of abstinence. Table 2. Results of the GEE Model Predicting Smoking Abstinence From Pretreatment Drinking Quantity, Tobacco Dependence, and Cocaine Use Table 3.