Glasgow 1981.

Methods	Setting: community, USA Recruitment: media advertisements
Participants	88 smokers (40 in self‐help conditions)
Interventions	Factorial trial of 3 different self‐help materials, with or without additional group support ∙ Danaher & Lichtenstein manual ∙ Pomerleau & Pomerleau manual ∙ I Quit Kit
Outcomes	Abstinence at 6 months Validation: CO < 15 ppm
Notes	3 different self‐help conditions and no strong hypothesis about direction of treatment difference between the Danaher & Lichtenstein manual and the Pomerleau & Pomerleau manual, so not used in the meta‐analysis of different programmes No statistical differences between quit rates (also included in group therapy review)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomly assigned"; method not described
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding (performance bias and detection bias) All outcomes	Low risk	Biochemical validation used; all groups received materials (differences in content only)
Incomplete outcome data (attrition bias) All outcomes	Low risk	3/88 lost to follow‐up; group not specified, so not included as smokers