Strecher 2005.

Methods	Setting: community, USA Recruitment: telephone callers to NCI Cancer Information Service, interested in quitting
Participants	1978 smokers; 70% female, average age 41 years, 46% smoked > pack/d, FTND 5.9
Interventions	All participants received approx 15 minutes of telecounselling Control ‐ single untailored 24‐page booklet (Clearing the Air) Intervention 1 ‐ single 8‐page tailored booklet, addressing motives and barriers cited by smoker Intervention 2 ‐ single untailored 24‐page booklet (Clearing the Air); multiple tailored materials (booklet, 2 newsletters, letter) at 5 months, 8 months, 12 months; tailored on baseline data Intervention 3 ‐ single untailored 24‐page booklet (Clearing the Air); multiple re‐tailored materials (same components and schedule as Intervention 2; used data from 5‐month follow up for re‐tailoring)
Outcomes	Abstinence at 12 months (7‐day point prevalence, but had also reported abstinence at 5 months' follow‐up) Validation: none
Notes	To derive numbers quit, assumed equal numbers in each condition 2 plus 3 plus 4 vs 1 in tailored vs untailored Slightly more evidence of effect when multiple compared to single (3 plus 4 vs 1 plus 2), and also for re‐tailored materials amongst subgroup who were quit at 5 months
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised; method not described
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding (performance bias and detection bias) All outcomes	Low risk	Although no biochemical validation, all participants received same telecounselling and were unaware of other treatment conditions, so risk judged to be low
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only respondents at 5 months eligible for 12 months' follow‐up 56% loss at 12 months (but includes those smoking at 5 months); no difference by condition Losses included as smokers