Ahluwalia 2006.

Methods	Study design: factorial RCT (2 x 2) Location: USA Setting: urban community‐based clinic Recruitment: through clinic, media and community outreach efforts, including radio, television, gas pump, billboard advertising, community health fairs, posting signs in minority‐owned businesses and mailing of referral letters from physicians
Participants	Defining eligibility criteria?: African‐American or black adults who smoked 10 or fewer cigarettes a day for at least 6 months prior to enrolment (light smokers) Participant characteristics: 755 adult smokers; 505/755 (66.9%) female; mean age: 45; mean cpd: 7.5; nicotine dependence: mean Fagerstrom test for nicotine dependence (FTND) = 4.3 Motivation to quit?: motivated
Interventions	Control 1: Health Education plus 2 mg nicotine gum (HE + NG): HE was a standard counselling approach, based on the current US Department of Health & Human Services treatment guidelines that focused on providing information and advice. Participants received the counselling over six 20‐minute sessions (three in‐person visits and three telephone calls). During HE sessions, trained counsellors used the ‘KIS II Quit Smoking Guide’ (a 36‐page booklet developed for African‐American light smokers) and semi‐structured scripts to review the addictive nature of nicotine, health consequences of smoking and benefits of quitting, and provided concrete strategies on developing a quit plan and identifying alternatives against triggers to smoke. Participants were provided with an eight‐week supply of 2 mg nicotine gum. Control 2: Health Education plus placebo gum (HE + PG): As control 1, however participants received placebo gum rather than 2 mg nicotine gum. Intervention 1: Motivational Interviewing plus 2 mg nicotine gum (MI + NG): MI counselling was provided by trained counsellors over six 20‐minute sessions (three in‐person visits and three telephone calls). Counsellors followed semi‐structured scripts that explored the pros and cons of smoking/quitting, and motivation and confidence to quit. A values clarification strategy based on the work of Miller & Rollnick was used. Participants also received the 36‐page ‘KIS II Quit Smoking Guide’. Intervention 2: Motivational Interviewing plus placebo gum (MI + PG): As intervention 1, however participants received placebo gum rather than 2 mg nicotine gum. Provider: trained counsellors (counsellors participated in two days of in‐service training). All counsellors participated in weekly group supervision to ensure the integrity of the respective counselling protocols. Intensity: counselling took place during six 20‐minute sessions (3 face‐to‐face and 3 telephone) over 16 weeks in all study arms. Was MI fidelity monitored?: Yes. Each session was tape‐recorded to maintain fidelity and consistency throughout the study. A subset of audiotapes were rated by investigators for adherence to MI principles using a modified version of the Motivational Interviewing Skills Code (results not reported). MI counsellors and supervisors reviewed audiotapes and discussed current issues at their weekly meetings.
Outcomes	Definition of cessation used: 7‐day point prevalence Length of longest follow‐up: 26 weeks Validation: saliva cotinine‐verified. A salivary cotinine cut‐off of ≤ 20 ng/mL was used. Was mental health and/or well‐being measured at follow‐up?: No Was quality of life measured at follow‐up?: No
Funding source	National Cancer Institute at the National Institutes of Health (R01CA091912). Glaxo‐SmithKline provided study medication but played no role in the design, conduct of the study or interpretation and analysis of the data.
Author conflicts of interest	None
Notes	For purposes of analysis, the two HE groups and the two MI groups were merged to create one HE group and one MI group. This was acceptable as there was no interaction detected between study factors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "a computer‐generated random‐numbers table was used to randomize patients".
Allocation concealment (selection bias)	Unclear risk	Quote: "a sealed envelope with pre‐assigned randomization numbers was drawn to determine which form of counseling the participant would receive". Did not state that envelope was opaque.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Smoking outcome was biochemically verified.
Incomplete outcome data (attrition bias) All outcomes	Low risk	18.8% lost to follow‐up in MI groups; 12.5% lost to follow‐up in HE groups. Therefore, less than 50% overall and similar loss to follow‐up between intervention groups of interest.