Meyer 2008.

Methods	Setting: primary healthcare centres, Germany Recruitment: smoking patients attending practices during 3 study weeks
Participants	Smokers, unselected for motivation; 48% female, average age 34, average cpd 16
Interventions	∙ Assessment only control ∙ Up to 3 letters individually tailored to SoC ‐ first used baseline assessment; 3 months and 6 months depended on further assessment; stage‐matched self‐help manuals used ∙ Brief physician advice and self‐help manuals
Outcomes	Abstinence at 24 months (sustained for 6 months) Validation: none
Notes	Analyses in paper allowing for clustering yield slightly larger estimates than use of crude numbers on quitting Different assumptions about losses to follow up did not substantially alter any results Abstinence rates increased over time in all groups Prolonged abstinence at all follow‐ups is very low ‐ not used here; 63% got 3 letters, 21% got 2, and 17% only 1
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quasi‐random and clustered based on time of attendance; fixed sequence of assessment‐only, tailored letters, advice; at least 2 weeks between study weeks
Allocation concealment (selection bias)	High risk	Condition known at the time of recruitment All patients screened, so recruitment bias should have been avoided; no evidence of differences in baseline characteristics
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No validation but practice team, practitioner, and follow‐up interviewers all blinded; however unclear if control participants were aware of what intervention participants were receiving
Incomplete outcome data (attrition bias) All outcomes	Low risk	56% of intervention group and 64% of control group reached at 24 months; different approaches to missing data did not alter conclusions