Elkins 2006.

Methods	Site: USA; most authors worked for Scott and White Memorial Hospital and Clinic, Temple, Texas. Study period: not stated. Recruitment: physician referral and advertisements. Sample size calculation: not mentioned (pilot study).
Participants	Number of participants: 20 smokers (number in group not specified, no response from author. Assumed 10/group in analysis). Inclusion criteria: at least 18 years, smoking ≥ 10 CPD, interested in quitting smoking in the next 30 days, able to attend weekly sessions, spoke English. Exclusion criteria: regular use of any non‐cigarette tobacco product, reported current abuse of alcohol or psychoactive drugs, current use of any other smoking‐cessation treatments, any reported history of borderline personality disorder, or currently using hypnotherapy for any reason. Overall demographics: average age early to mid‐40s, majority female, Caucasian, married, high school education; > 20 CPD; Fagerstrom score of slightly > 10.
Interventions	a) Intensive hypnotherapy ‐ 8 x 1 hour sessions of hypnotherapy (9 steps hypnotic induction) plus self‐hypnosis tape for daily practice. b) Waiting‐list control. Both groups: National Cancer institute self‐help materials, encouraged to set TQD, 3 x 5 to 10 mins supportive phone calls at weeks 2, 4 & 5. Duration of intervention: approximately 2 months.
Outcomes	Definition of smoking cessation: 7‐day point‐prevalence abstinence at week 26. Adverse events: no information provided on whether or not AE data were collected and whether any AEs occurred.
Notes	Funding: not stated. Author declaration of interest: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomized, method not stated
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding not possible due to nature of intervention, but cessation was biochemically verified: CO 8 ppm or less at each visit. If CO value greater than 8 ppm, saliva cotinine had to be less than 20 ng/mL.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Authors stated they conducted an ITT analysis with participants unavailable for assessment counted as non‐abstainers; no data were provided on dropout rates so it is not known if there was differential dropout between groups.
Selective reporting (reporting bias)	Low risk	All outcomes reported as described in the methods section.