Bock 2019.

Study characteristics
Methods	Study design: RCT Location: USA Setting: community Recruitment: advertisements on local radio stations and websites, flyers and brochures at physician’s offices and stores Study dates: not reported
Participants	N = 227 Specialist population?: no Definition of smoker used: ≥ 5 cpd Participant characteristics: 56% female; average age: 46 years; 86% white; 28% high school education or less; average cpd: 17; nicotine dependence: average FTND 4.9
Interventions	All participants were provided with an 8‐week group CBT programme for smoking cessation, including planning for a targeted quit day (week 4), handling smoking triggers, coping with cravings, and managing withdrawal. Comparator Group CBT + wellness classes Mode of delivery: face‐to‐face (group) Intensity: 8 CBT sessions (x 1 h) and 16 wellness classes (x 1 h) over 8 weeks Pharmacotherapy: none provided, but participants were permitted to use NRT or other smoking cessation medications in conjunction with the programme Type of therapist/provider smoking cessation counselling: PhD‐level psychologists wellness: wellness counsellor or other healthcare professional (e.g. sleep expert) BCTs: 1.1 Goal setting (behaviour), 1.2 Problem solving, 3.1 Social support, 12.6 Body changes Intervention Group CBT + Iyengar yoga Mode of delivery: face‐to‐face (group) Intensity: 8 CBT sessions (x 1 h) and 16 yoga classes (x 1 h) over 8 weeks Pharmacotherapy: none provided, but participants were permitted to use NRT or other smoking cessation medications in conjunction with the programme Type of therapist/provider smoking cessation counselling: PhD‐level psychologists yoga: certified Iyengar instructors with > 15 years' experience BCTs: 1.1 Goal setting (behaviour), 1.2 Problem solving; 3.1 Social support (unspecified)
Outcomes	Definition of abstinence: continuous (based on 7‐day point prevalence at end of treatment and follow‐up) Longest follow‐up: 6 months Biochemical verification: CO < 10 ppm or salivary cotinine < 15 mg/mL Other relevant outcomes reported: none
Notes	Relevant comparisons: Iyengar yoga + CBT vs wellness classes + CBT Funding source: National Institutes of Health, National Center for Complementary and Integrative Health (R01 AT006948) Author conflicts of interest: “The authors have no competing financial interests to declare.”
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote [protocol]: “The randomization scheme generated by the study statistician uses a permuted block randomization procedure, with small, random sized blocks. Randomization is stratified based on gender and level of nicotine dependence.”
Allocation concealment (selection bias)	Unclear risk	Concealment not reported
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Abstinence biochemically verified
Incomplete outcome data (attrition bias) All outcomes	Low risk	At 6‐month follow‐up 6.2% (7/113) were lost to follow‐up in the intervention group and 4.4% (5/114) in the control group
Selective reporting (reporting bias)	Low risk	Prespecified outcomes reported