Fee 1977.

Methods	Site: UK, an anti‐smoking clinic in Tayside, Scotland. Study period: 1970 to 1972. Recruitment: personal application or hospital or GP referral. Sample size calculation: not mentioned.
Participants	Number of participants: 232 smokers (hypnosis: 57; aversion: 60; fenfluramine: 58; placebo: 57). Inclusion criteria: not stated. Exclusion criteria: not stated. Overall demographics: no information reported.
Interventions	a) Individual hypnosis b) Aversion therapy (covert sensitisation) c) Fenfluramine d) Placebo There was a standard 9‐week course treatment for all intervention groups. Number and duration of sessions not stated; treatment method details not provided.
Outcomes	Definition of smoking cessation: point‐prevalence abstinence at 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
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding and self‐report only
Incomplete outcome data (attrition bias) All outcomes	High risk	Participants who did not complete treatment were excluded from the original analysis: a) 19 (33%); b) 23 (38%); c) 32 (55.2%) and d) 33 (58%). Dropout rates were high, and there were more treatment dropouts in "fenfluramine" and "placebo" groups than the other two treatment groups. We included all participants in our recalculations following protocol for ITT analysis. Those with missing data were assumed to be smoking.
Selective reporting (reporting bias)	Low risk	All outcomes reported as described in the methods section.