Webb 2013.

Methods	Setting: community, USA Recruitment: community volunteers
Participants	424 current smokers of ≥ 5 cpd, 57% female, average age 42 years, average cpd 19.7
Interventions	Both groups received 2 priming phone calls explaining benefits of intervention and encouraging use of materials. In intervention, priming call explicitly stated materials were tailored ∙ 4 self‐help booklets with placebo tailoring, covering cigarette smoking, cessation, and relapse prevention, based on cognitive‐behavioural techniques ∙ 4 standard self‐help booklets covering same materials
Outcomes	1 month sustained abstinence at 6 months Validation: CO ≤ 8 ppm for locals
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not specified
Allocation concealment (selection bias)	Unclear risk	Not specified
Blinding (performance bias and detection bias) All outcomes	Low risk	Biochemical validation used; interventions of similar intensities
Incomplete outcome data (attrition bias) All outcomes	Low risk	29% lost in intervention group, 25% lost in control group