van der Aalst 2012.

Methods	Setting: community, Belgium and the Netherlands Recruitment: subgroup of participants enrolled in lung cancer screening trial; identified via population registry
Participants	1284 currently smoking male participants of lung cancer screening trial, 50 to 75 years old, smokers of > 15 cpd for > 25 years or > 10 cpd for > 30 years 100% male, average age 57, average cpd 18, 55% not planning to quit within 6 months
Interventions	∙ Computer‐tailored smoking cessation advice via mail (one‐off), sent only to participants who completed questionnaire after randomisation ∙ Standard brochure (35 pages; Smoking Cessation, Why and How)
Outcomes	Continuous abstinence at 2 years (prolonged; point prevalence also reported) Validation: none
Notes	Participants had to return questionnaire before receiving tailored brochure – only 23% did so (147/642) In this subset, quit rates were slightly higher (14.3% prolonged as compared to 12.5% in total intervention group) but were still less than in control group and no significant difference
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	Not blinded, but at assessment, majority of participants were unaware of which they had been assigned to; differential misreport judged to be unlikely
Incomplete outcome data (attrition bias) All outcomes	Low risk	84% intervention and 85% control followed up at 2 years