, 1996; Everson, Kaplan, Goldberg, & Salonen, 2000). Metric measurements of height and weight were collected to calculate body mass index. currently CO and serum cotinine were assessed as biomarkers of baseline tobacco use. Smoking history assessment included the current number of cigarettes smoked per day, age of regular smoking, amount spent on cigarettes per week, daily or nondaily smoking, and type of cigarettes smoked (mentholated or nonmentholated). Quitting history was assessed by asking the number of quit attempts in the past year that lasted 24 hr or longer (Ahluwalia et al., 2006; Ahluwalia, Harris, Catley, Okuyemi, & Mayo, 2002; Ahluwalia, Richter, Mayo, & Resnicow, 1999). Motivation and confidence for quitting were assessed using a 10-point Likert scale with a higher score indicating greater motivation or confidence (Ahluwalia et al.
, 1999, 2002, 2006). Nicotine dependence was assessed using one item from the Fagerstr?m Test for Nicotine Dependence scale that asked about time to first cigarette of the day (Heatherton, Kozlowski, Frecker, & Fagerstr?m, 1991). Participants were also asked the number of their five best friends who smoked cigarettes. The Questionnaire of Smoking Urges (Cox, Tiffany, & Christen, 2001) was used to assess urge to smoke. Mental health measures included psychiatric comorbidities assessed with the Rost�CBurnham screener for past year depression (Rost, Burnam, & Smith, 1993), the 9-item patient health questionnaire (PHQ-9) for depression in past 2 weeks (Kroenke & Spitzer, 2002), and the 4-item perceived stress scale for stress in past 30 days (Cohen, Kamarck, & Mermelstein, 1983).
Furthermore, study participants were asked questions on drug treatment history and drug and alcohol dependence with the Rost�CBurnham screener for lifetime drug (marijuana, cocaine, and heroin) and lifetime alcohol dependence (Rost et al., 1993). Cognitive impairment was assessed with the Short Blessed Test (Katzman et al., 1983), a 6-item test for differentiating cognitive impaired patients from normal population. Analysis We calculated the descriptive statistics of the baseline sociodemographic and homelessness characteristics, smoking and other drug use characteristics, and general and mental health profile for the study sample. Categorical variables were summarized by frequencies and percentages, and continuous variables were summarized by means and SD.
Results A total of 839 individuals who indicated interest in the study completed the eligibility survey. Batimastat Of these, 568 (67.7%) were eligible. Among those eligible, 138 (24.3%) participants did not keep their randomization appointment. The remaining 430 (75.7%) were randomized into the two study conditions over a 15-month period. Figure 1 shows the flow of events from assessment of eligibility through randomization.