Davis 1992.

Methods	Setting: community, USA Recruitment: advertisements for the Cancer Information Service hotline
Participants	Women smokers with children under 6 calling hotline; results based on 630 of 873 (72%) of those recruited who were followed up at 6 months
Interventions	∙ Quitting Times, a self‐help guide developed to meet the special needs of women smokers with young children (65 pages in magazine format) ∙ ALA: Freedom from Smoking for You and Your Family ∙ National Cancer Institute: Clearing the Air
Outcomes	Abstinence at 6 months (7‐day point prevalence) Validation: no biochemical validation; confirmation by surrogate; those refusing to give a surrogate were classified as smokers
Notes	Does not contribute to main analysis, 1 vs 2 and 3; impact of targeting to population All 3 guides covered similar topics; no significant differences were found between any of them
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	"Preassigned list randomized by day of week"
Allocation concealment (selection bias)	Low risk	Counsellors who recruited participants during calls were blinded to the self‐help guide that would be received
Blinding (performance bias and detection bias) All outcomes	Low risk	All groups received self‐help, so similar levels of intensity "Follow‐up interviews were conducted by trained interviewers who were blinded regarding subject assignment.... Surrogate interviews were conducted to verify the smoking status of those who reported that they had quit smoking..."
Incomplete outcome data (attrition bias) All outcomes	Low risk	72% of participants reached at follow‐up; similar for all 3 groups Analyses based on those reached