Lambe 1986.

Methods	Site: USA, Family Medicine Center (FMC); patient population was representative of cross‐section of Monroe Country, New York. Study period: not stated. Recruitment: patients attending FMC for scheduled health care screened for eligibility. Sample size calculation: 180 participants needed for 90% power. Assumed effectiveness of advice alone 5%, hypnosis 20% effective; allowed for 10% dropout ; one‐tailed alpha error of 0.05.
Participants	Number of participants: 180 smokers (90 in each group). Inclusion criteria: wish to quit smoking and willing to undergo hypnosis. Exclusion criteria: aged < 18 years; psychiatric diagnosis. Overall demographics: mean age approximately 35 years; majority female; mean CPD approximately 26.
Interventions	a) Hypnosis (2 x 40min sessions (probably individual), 2 weeks apart. Instructions for autohypnosis; for those who accepted hypnosis treatment only). b) Cessation advice control (letter from physicians advising quitting, copy of 'Calling It Quits' booklet). All subjects received 3 telephone calls in first 4 months to offer encouragement and ascertain smoking behaviour. Duration of intervention: 4 months. Duration of follow‐up: 12 months.
Outcomes	Definition of smoking cessation: point‐prevalence abstinence at 6 and 12 months. 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, but Zelen design (18 subjects declined hypnosis but analysed in hypnosis group)
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding of outcome assessment (detection bias) All outcomes	High risk	Unblinded, self‐report only
Incomplete outcome data (attrition bias) All outcomes	Low risk	Lost to follow‐up: at 6 months: a) 24; b) 26: At 12 months: a) 30; b) 30. Only patients who could be contacted at each follow‐up period included in the original analysis. About the same number of patients lost to follow‐up across groups at 6 and 12 month follow‐up. Numbers of quitters derived from percentages, corrected for dropouts. Recalculations included all participants following ITT protocol; missing assumed smoking.
Selective reporting (reporting bias)	Low risk	All outcomes reported as described in the methods section.
Other bias	Unclear risk	Baseline imbalances may have favoured intervention group but analyses did not investigate this. Patients in hypnosis group tended to be younger, more educated, less likely to have Medicaid.