Batra 2013.

Methods	Setting: community, via University Hospital Tubingen and University of Hamburg, Germany. Study period: October 2010 to February 2012. Recruitment: participants recruited via advertisements in local media and university email campaigns. Sample size calculation: not described.
Participants	Number of participants: 360 smokers (180 in each group). Inclusion criteria: current smokers prepared to stop smoking and who have smoked ≥10 CPD for the previous two years. Exclusion criteria: severe mental health disorder (e.g. psychotic disorder, bipolar disorder, PTSD, current major depression, current alcohol or drug dependence); use of any tobacco products other than cigarettes; participation in any smoking cessation treatment within the past six months; current pregnancy or breastfeeding. Overall demographics: predominantly women (60%); mean age 43 years; mean CPD = 19; mean years as smoker = 26.5; mean FTND = 6.2.
Interventions	a) Hypnotherapy ‐ trance‐induced and including: focusing on the desired internal and external condition, developing a positive self‐perception, reframing of smoking behaviour and relapses, and posthypnotic suggestions to connect cognitive and emotional sensations in trance with daily life and self‐hypnosis to strengthen imagination of living without cigarettes b) Cognitive behavioural therapy (CBT) ‐ including: psychoeducation, self‐monitoring of smoking behaviour, identification of smoking cues and smoking‐associated situations, functional analysis of smoking behaviour, motivational enhancement strategies, developing alternative behavioural options, self‐control and stimulus‐control strategies, reinforcement of abstinence, strategies to cope with smoking urges and withdrawal, relapse prevention strategies and strategies to cope with relapse. Both interventions were delivered by clinical psychologists as group sessions with 7 to 9 participants per group. Both interventions were delivered as one 90‐minute session per week for six weeks. Quit date was set to be between weeks 2 and 3 of treatment. Participants received EUR 10 for attending the 1‐ and 12‐month follow‐up sessions, and EUR 50 at the 12‐month follow‐up if they had completed all follow‐up assessments.
Outcomes	Definition of smoking cessation: Russell standard abstinence at 12 months (no more than 5 cigarettes and a CO reading < 10 ppm). Adverse events: no information provided on whether or not AE data were collected and whether any AEs occurred.
Notes	Funding: not described. Author declaration of interest: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were assigned to CBT or hypnotherapy via block randomization procedure
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemically validated so differential misreport judged unlikely
Incomplete outcome data (attrition bias) All outcomes	Low risk	If questionnaires were not returned, or CO measurement not available or > 9ppm, participants were considered smoking (but could have been successful quitters). CO measurement was available at 1 m and 12 Tm for 66.6 and 71.0% of participants, respectively. Around 20% of each group was LTFU by 52 weeks (CBT 78.8% and hypnotherapy 82.8% response at 12m follow up)
Selective reporting (reporting bias)	Unclear risk	A translation of the Methods document for the study, provided by the author, lists the data collection instruments to be used for the trial; some of the baseline variables collected, and the Minnesota Nicotine Withdrawal Scale‐Revised do not appear to be reported in the translation of the Results report. As the study is unpublished, the reason for this omission is unclear.