This phase 1 efficacy study is a 2 (intervention) × 4 (time) mixed factorial design with cotinine-confirmed cessation as the primary outcome. Factor 1 is the type of intervention: culturally specific CBT (CS-CBT) versus standard CBT (control), both supplemented by 8-weeks of transdermal nicotine patch (TNP) therapy. CBT in both conditions consists of cognitive and behavioral strategies guided by evidence-based smoking cessation and relapse prevention models (Marlatt & Gordon 1985). The key difference between conditions is whether the intervention is culturally specific. The culturally specific components (e.g., discussion of race and smoking, race-matched clinicians, and an emphasis on religion/spirituality) are those described in the literature and our prior research. Factor 2 is time: End-of-counseling (EOC), and 3, 6, and 12-month post counseling assessments. This study includes a controlled, internally valid, experimental test of the efficacy of CS-CBT among African American smokers. Figure 1 illustrates the flow of participants through the trial.
Participants and recruitment
Participants will be 247 African American tobacco smokers recruited from the community. We developed a comprehensive recruitment plan, consisting of advertisements on public transportation, partnering with healthcare organizations with large racial minority clientele, and street outreach (directly talking with people in predominantly Black neighborhoods and visiting local businesses). Participants are considered eligible if they: (1) self-identify as African American; (2) currently smoke ≥ 5 cigarettes/day or have an expired CO level of ≥ 8 ppm; (3) are ages 18–65; (4) are able to read 5th-6th grade English; (5) have permanent contact information; (6) are able to attend clinic sessions (transportation costs are reimbursed); and (7) are motivated to quit smoking (rated as a 6 on a 1–10 scale). We exclude those who are currently receiving any type of cessation, alcohol or illicit drug treatment, pregnant/breastfeeding, or diagnosed with an acute cardiac or respiratory condition. Ineligible participants are referred to the Florida QuitLine.
Eligible participants are randomly allocated using a 1:1 ratio in blocks of 50 to one of the two conditions, CS-CBT or control. The unit of randomization is the individual. Eligible participants receive a tentative random assignment and are scheduled for an orientation session, with only those who attend and provide written informed consent enrolled in the study. We schedule up to 25 participants per group to ensure 8–12 tentatively assigned participants are enrolled/consented into the study.
Prior to orientation, welcome letters containing the schedule of group sessions and directions are mailed. Reminder calls are placed to facilitate continued interest in the study. Participants attend orientation, eight clinic sessions, and 3, 6, and 12-month follow-up assessments.
Orientation and intervention sessions
Participants attend a 60-minute orientation before the start of the clinic sessions. They learn the background, purpose, format, and procedures of the study; provide informed consent; complete baseline measures; learn about TNP therapy and receive their first patch (the remainder of the patches are provided throughout active treatment); and provide breath carbon monoxide (CO) and saliva samples for cotinine analysis. We also cover smoking and health, self-motivation, and goal setting. In the CS-CBT condition, we explain that the group is framed within a cultural context, designed to emphasize African American race/ethnicity and cultural issues.
In accordance with previous research (Webb et al. 2010;Brandon et al. 1995) participants in both conditions are asked to reduce their smoking by one-half on the day before the first clinic session and to abstain completely from smoking on the first day of actual group treatment (session 1). They are also instructed to begin patch use on the morning of the first day of treatment (session 1; the target quit day) with the patch provided at orientation. This aspect of the protocol is unique from other cessation approaches that set the quit day several weeks post beginning the intervention. However, this evidence-based protocol has been successful in previous studies [e.g., Webb et al. 2010; Brandon et al. 1995 and is also the format we use in our ongoing cessation clinic. Participants who do not quit on the target day are encouraged to make a quit attempt by the third treatment session.
Participants in both conditions meet eight times over four consecutive weeks. Four sessions occur during week 1, two during week 2, and one weekly booster session during weeks 3 and 4. Depending on group size, the duration of sessions is 90–120 minutes in both conditions. We anticipate 8–16 participants per group. Co-therapy pairs of masters or bachelor’s level interventionists are trained to conduct sessions for one condition (CS-CBT or control) and supervised by the principal investigator (PI). Groups are held in a laboratory-based clinic. Incentives include $40 at session 1, $20 at session 5, $50 at session 8, $50 at the 3-month assessment, $70 at the 6-month assessment, and $70 at the 12-month assessment. Participants also receive $5 per session for transportation/parking and light refreshments at each session.
Group cognitive behavioral therapy for smoking cessation (control): The intervention in this condition is based on standard cognitive and behavioral strategies, supplemented by TNP therapy. A previous study testing this intervention in an African American sample found 7-day ppa rates of 70% at the EOC, 52% at the 3-month follow-up, and 46% at the 6-month follow-up post counseling (Webb et al. 2010). Session content is displayed in Table 1, and includes the benefits of quitting, nature of nicotine addiction, nicotine withdrawal, identification of “high risk” situations, motivation, coping skills, stress and negative affect, decision making, alcohol use, weight control, social support, behavioral contracting, and relapse-prevention. To enhance the external validity of the intervention, the co-therapy team is not race-matched (at least one interventionist is non-African American/Black).
Culturally specific group cognitive behavioral therapy for smoking cessation (CS-CBT): The intervention is the standard CBT program with an emphasis on African American culture (Table 1). Each session focuses on specific aspects of traditional African American culture. The CS topics were selected based on our previous qualitative research (Webb et al. 2007), and established models e.g. (Robinson et al. 1992). Topics include deep structure: Distrust for biomedical research; race and smoking, race-based statistics related to nicotine replacement/medication concerns; religion/spirituality; family/collectivism; unique stressors; racism/discrimination, depression among African Americans; co-morbid addiction; neighborhood/environmental influences; targeted tobacco marketing; menthol cigarettes; race-specific weight issues and concerns; and working as a community against the tobacco industry. Surface structure is also included: Interventionists are race-matched, second-person phrases (e.g., us, we) are used throughout, and the daily agenda includes African American quotations or proverbs.
Transdermal nicotine patch therapy (TNP)
TNP has demonstrated efficacy in multiple trials (Silagy et al. 2000), is available over-the-counter, and is safe and effective for smoking cessation (Shiffman et al. 2002) without monitoring by a physician. Consistent with (Webb et al. 2010) and (Fiore et al. 2008), participants are prescribed four weeks at 21 mg, two weeks at 14 mg, and two weeks at 7 mg (Doses are adjusted according to smoking history).
Training and intervention fidelity
The interventionists are trained by the PI. Training includes relevant readings (smoking, cessation and relapse prevention, cognitive behavioral therapy, motivational interviewing), observation of two therapy groups, minimal contributions in the role of therapist, and finally, fully conducting sessions with weekly PI supervision. Detailed intervention manuals are followed closely and participants receive a daily agenda. Interventionists do not cross over to prevent contamination. Most sessions are audio recorded and will be coded using a 10-item scale for adherence [see Webb et al. 2010 by two independent evaluators. Codes will be transformed into percentages indicating the degree of protocol adherence.
Measures include demographics, smoking history, and nicotine dependence (Heatherton et al. 1991) (Table 2). We also assess perceived stress (Cohen et al. 1983), depressive symptoms (Radloff 1997), and decision making. Particularly relevant for African American smokers, we include assessments of acculturation (Klonoff & Landrine 1999), ethnic identity (Davis et al. 2010), expectancies for culturally specific interventions, and perceived ethnic discrimination (Landrine et al. 2006). We also record height and weight. Participants also complete an “In Case I Move Form” as a method of tracking participants via relatives or friends.
Attendance, TNP utilization, and weight are recorded at each session. Participants also self-report, via monthly telephone follow-ups, utilization of 14mg, and 7mg patches across the full 8-weeks. The Minnesota Withdrawal Scale (Hughes & Hatsukami 1986) is administered as an indicator of nicotine withdrawal, and the Questionnaire of Smoking Urges-Brief (Sanderson Cox et al. 2001) assesses urges to smoke.
Participants evaluate the intervention, using the Intervention Rating Questionnaire (Webb et al. 2010), and complete measures of perceived stress, depressive symptoms, nicotine withdrawal, and therapist satisfaction (Oei & Green 2008) (Table 2). Self-reported smoking status since the target quit date is assessed using the time-line follow-back (TLFB) procedure, which reconstructs the participant’s smoking pattern since the target quit date (Brown et al. 1998;Sobell & Sobell 1992).
Follow-up (3, 6, and 12-months)
Measures completed at each “reunion meeting” include the TLFB (Brown et al. 1998;Sobell & Sobell 1992), smoking status and use of other tobacco products and pharmacotherapy, and weight (Table 2).
Smoking status is confirmed biochemically. Cotinine assays are collected at the orientation meeting (for a baseline level before cessation) and at the in-person 3, 6, and 12-month follow-ups (for self-reported quitters). Cotinine samples, using a cut point of 7 ng/ml, will determine smoking status (Abrams et al. 1987;Etter et al. 2000). The CBT protocol requires that breath carbon monoxide (CO) samples be collected at each session to provide participants with immediate feedback. Breath CO readings of at least 8 ppm will distinguish smokers from nonsmokers at the EOC, and have been found to be a sensitive method of determining smoking status (Benowitz et al. 2002). As recommended by (Benowitz et al. 2002), follow-up abstinence rates will be calculated separately for both self-report and biochemical findings.
The primary outcome variable is 7-day ppa, assessed at the EOC, 3, 6, and 12-month follow-ups. Seven-day ppa refers to no smoking (not even a puff) for the past seven days (Hughes et al. 2003). Secondary outcomes include 24-hour (no smoking in the past day) and 28-day continuous abstinence (no smoking over the past 4 weeks).
Sample size and power
Sample size was determined based on Webb et al. (2010) and the formula provided in (Diggle et al. 2002) (p. 31). Webb et al. 2010 found that 51% of participants who received standard CBT reported 7-day ppa at the EOC, and about a 20% relapse rate at 3-months and 6-months. In the CS-CBT pilot study, we found 75% 7-day ppa at the EOC. Assuming a 23% reduction at 3-months, four assessments, with a within-subjects correlation of .60, 65 participants per group will yield power = .80% with a two-sided significance level of 5%. We conservatively anticipated 30% 7-day ppa at 12-months in the CS-CBT condition, and 14% in the control condition. To examine acculturation and ethnic identity as moderators controlling for covariates (e.g., group, sociodemographic factors, etc.), the planned regression analyses require a sample of 124. Thus, the final N is 150 (completing all assessments).
Preliminary analyses will include graphics/plots, and descriptive statistics. We will compute frequencies and proportions for retention and baseline characteristics, and use t-tests and chi-squared tests to evaluate differences. Alpha will be set to .05, and adjusted for multiple comparisons. Missing values will be handled with appropriate methods (Little & Rubin 2002). Outcome analyses will be conducted with (a) an intent-to-treat (ITT) approach, in which participants with missing data are assigned the status of smoker, and (b) a “per protocol” approach, which will include participants who complete all aspects of the study; (orientation, ≥ four intervention sessions, and all follow-ups). Within-time logistic regressions will determine the odds of abstinence at each assessment, comparing CS-CBT to control. Generalized linear mixed modeling (GLMMs) will examine between-group cessation rates over time, including main effects and interactions, and accounting for nesting within groups. A pattern-mixture analysis will examine whether intervention effects differ according to patterns of missing data (e.g., those who complete only one follow-up). Hierarchical logistic regression will be conducted to explore ethno-cultural predictors of cessation.
Ethics and safety
This study is being conducted with University of Miami Institutional Review Board approval. We undergo careful screening to attempt to identify respondents who are not appropriate for the study due to medical concerns that preclude TNP use (e.g., pregnant women, acute cardiac events). During the 1-year duration of the trial, participants may contact the research team in the event of an adverse event. During orientation, participants are advised to seek prompt medical attention in the case of severe side effects from the TNP or other unexpected emergency. Over the course of the intervention and follow-ups, nicotine withdrawal is monitored, in addition to the discussion of medical symptoms.