Villebro 2008.

Methods	Setting: Pre‐surgical assessment clinic, Denmark Recruitment: Smokers due to undergo elective hip or knee replacement surgery, not selected for motivation
Participants	120 daily smokers; 57% F, av. age 65, av. cpd 15; no information about baseline motivation Provider: trial nurse specialist
Interventions	Intervention: weekly counselling from 6‐8 weeks prior to surgery to 10 days post‐op. Individualised NRT. Strong encouragement to quit but option to reduce consumption by ≥50%. Control: Standard care
Outcomes	Abstinence 1 year after surgery Validation: CO only for those who participated in focus group interviews
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Stratified block randomisation
Allocation concealment (selection bias)	Low risk	Opaque sealed envelopes
Incomplete outcome data (attrition bias) All outcomes	Low risk	4/60 I & 15/60 C not reached at 1y, included as smokers