Prochaska 2004.

Methods	Setting: community, USA Recruitment: parents of ninth grade students in a separate study; at risk for one of the targeted health behaviours
Participants	711 smokers from total of 2460 participants; 75% female (full sample), average age 43 years (full), average cpd 18, 41% at pre‐contemplation phase, 41% contemplators, 18% in preparation
Interventions	∙ Assessment only (completed questionnaires on 3 occasions) ∙ Expert system ‐ tailored 3 to 5‐page report at 0 months, 6 months, and 12 months and manual
Outcomes	Abstinence at 24 months sustained for 6 months (other measures of abstinence also reported) Validation: none
Notes	2 vs 1, tailoring
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	No information on blinding provided; no validation; interventions at different levels of intensity, so differential misreport judged possible
Incomplete outcome data (attrition bias) All outcomes	Low risk	Slightly higher loss to follow‐up in Intervention (45%) than in control (40%) All participants included in this meta‐analysis