Clark 2004.

Methods	Randomised controlled trial Location: USA Funding: Grant from the National Cancer Institute Recruitment: current smokers undergoing low‐dose fast spiral chest CT (SCTS) for lung cancer. Participants were recruited at the first annual follow‐up visit
Participants	171 current cigarette smokers (85 intervention group, 86 control group), had access to a computer with Internet service. Average age 57.4 years, 50% female, 60% of participants were smoking < 20 CPD
Interventions	Intervention: Hand‐out with a list of 10 Internet sites related to stopping smoking and a brief description of each site Control: received a copy of a publication of the National Cancer Institute
Outcomes	Long‐term abstinence: 7‐day PPA at 12‐months Short‐term abstinence: 7‐day PPA at 30 days Validation: CO measurement at 12‐month follow‐up Other reported outcomes: readiness to quit if not stopped, other tobacco use, number of quit attempts in previous year, other smokers in household, utilisation of intervention materials at 30‐day follow‐up
Notes	Not included in any analyses, as intervention extremely low intensity and similar to control arms of other trials (self help).
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 in the paper
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts, as all study participants attended their annual review which corresponded with the 1‐year follow‐up assessment