Skov‐Ettrup 2016.

Methods	Randomised controlled trial Location: Denmark Funding: The study was funded by the Danish Cancer Society Recruitment: Participants were recruited from the Danish Health Examination Survey (2007 – 2008) and the Danish Health and Morbidity Survey (2010). No incentive was offered for participation. Participants were enrolled from August to October 2011. Follow‐up was completed in January 2013.
Participants	Participants (n = 1810) (Proactive telephone counselling n = 452; Reactive telephone counselling n = 453; Internet‐based program n = 453; Booklet n = 452) were self‐reported daily smokers, with a Danish address in 2011, valid email address and mobile phone number. Participants were aged 41 ‐ 62 years. No other overall baseline characteristics were reported.
Interventions	Intervention: 'e‐quit' was a tailored and interactive Internet intervention, with optional text message support, accessed freely online for the duration of the study. Upon signing up to the intervention webpage all participants received a tailored feedback letter based upon their level of dependence, and users were encouraged to select a quit date within the next 3 months. The website included personalised feedback according to quit date and overview of programme components, a daily video of a person at the same stage of the smoking cessation process, exercises for increasing motivation and identifying coping strategies, tailored feedback based on level of dependence (pharmacotherapy was encouraged for those with high nicotine dependence), blog option, action planning tool, urgent assistance for cravings and information about smoking and health emails and text messages from e‐quit were optional. Proactive telephone counselling was a non‐internet‐based, active control arm, including 5 sessions delivered over 8 weeks. The intervention was based on 5 themes from the Transtheoretical Model of behaviour change: clarification (smoking history and readiness), preparation (strengthening of motivation and planning coping strategies), action (maintaining participant engagement during the first days as smokefree), action/maintenance (maintaining engagement and recognition of success), and future (maintenance and the future as non‐smoker). Participants were encouraged to set a quit date, and counsellors assessed nicotine dependence, informed about the pros and cons of using pharmacotherapy accordingly. Control: Reactive telephone counselling was a non‐internet‐based non‐active control arm in which interested participants received 1 session that lasted for approximately 13 – 15 minutes, no information about how many sessions were provided. Participants were informed that they could receive free telephone counselling at the Danish national quitline; callers who were ready to quit were encouraged to set a quit date and information about pharmacotherapy was provided if relevant
Outcomes	Outcome data were collected at 1, 6 and 12 months. Outcomes were non‐bioverified prolonged abstinence, and 30‐day PPA
Notes	No conflicts of interest were reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Allocation was conducted by applying a fixed sequence of 4 numbers repeatedly
Allocation concealment (selection bias)	High risk	Allocation was conducted by applying a fixed sequence of 4 numbers repeatedly. The person performing the allocation was blinded to names and ID numbers
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rates: 21% e‐quit; 21% proactive telephone counselling; 15% self‐help booklet