Prochaska 2001a.

Methods	Setting: managed care organisation, USA Recruitment: smokers identified by survey of members; 85% recruited to a study
Participants	1447 smokers (967 at 18 months' follow‐up); 56% female, average age 38, average cpd 20
Interventions	∙ Assessment only (completed questionnaires on 4 occasions) ∙ Expert system ‐ tailored 2 to 3‐page report at 0 months, 3 months, and 6 months, and SoC‐matched manual ∙ As second bullet above plus telephone counselling ∙ As third bullet above plus computer for scheduled cigarette reduction
Outcomes	Abstinence at 18 months, sustained for 6 months (other measures of abstinence also reported) Validation: none
Notes	2 vs 1, tailoring. 3 contributes to telephone counselling review; 4 not included Arm 2 is also evaluated in Velicer 1999 results
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	Unclear risk	Self‐reported outcomes from participants not blinded to treatment condition; treatment more intensive than control, and no information on blinding reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	MA includes losses to follow‐up and refusals Study author analysis suggests ITT analysis is biased Sensitivity analysis (comparison 99) tests impact on outcome