Schuck 2014.

Methods	Setting: Netherlands; school‐based Recruitment: Quote: "Smoking parents were recruited through their children’s primary schools across the Netherlands. Primary schools were contacted by research assistants and asked to distribute study invitation letters to parents through children." [...] "Parents registered to take part by mail, e‐mail, telephone or via a website."
Participants	512 daily or weekly smokers and parents or caretakers of a child aged between 9 and 12 years. They were considering quitting smoking (currently or in the future). 47.5% M, av. age 42.2, av. cigs/day 16.2
Interventions	1. "Standard Self‐Help Brochure: Participants received a 40‐page, colour‐printed self‐help brochure including didactic information on nicotine dependence and the health benefits of quitting smoking, tips and advice on how to initiate and maintain abstinence, instruction in the use of cognitive and behavioural skills to avoid triggers to smoke and cope with urges to smoke, and strategies for managing a lapse or relapse to smoking 2. Intensive Proactive Quitline Counselling + supplementary materials tailored to smoking parents; mean number of calls completed was 5.5 and these were scheduled for 10 days before quit day, 3 days, 1, 2, 4 weeks, 2, and 3 months after quit day." Quote: "In addition, all participants received three accompanying booklets entitled Smoke‐free parents which were designed for this study as tailored supplementary materials. Each booklet (four pages, colour‐print) contained didactic information, tips and advice, motivational messages, as well as ‘parent‐relevant information’; e.g. effects of second‐hand smoke (SHS) on children, strategies to manage parent‐specific stressors]."
Outcomes	Abstinence at 12 m (6‐m prolonged) Validation: breath CO and saliva cotinine analysis in a random subsample (36 out of 133)
Notes	New for 2018 update Funding: "This work was supported by ZonMW, the Netherlands Organization for Health Care Research and Development (grant number: 50‐50110‐96‐639)." Declarations of interest: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "To ensure equal group sizes, allocation was performed in blocks of 10. To ensure balance of key characteristics, stratified randomization was used based on the stratifying variables gender, educational level (low: no high school diploma/no vocational training, medium: vocational training or high school diploma, high: college degree) and cigarettes per day (fewer than 10, 10–20, 21 or more)."
Allocation concealment (selection bias)	Low risk	Quote: "Allocation of participants to trial conditions was conducted by an independent member of the research group using a computer‐generated allocation sequence." [...] "The independent researcher prepared a list of study participants and their allocated treatment. Based on this list, the first author prepared the mailings which informed study participants about the treatment they would receive."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemical validation not done in the entire sample, but just in a random subset. However, verified abstinence rate of 82% (18 of 22) overall in the subsample was acceptable, with no significant different across arms
Incomplete outcome data (attrition bias) All outcomes	Low risk	Even though "There was a significant difference in the follow‐up rate between treatment groups (85.5% in the quitline condition and 89.5% in the self‐help condition, χ2 = 4.98, P = 0.03)", overall attrition was low (11%). Furthermore "Participants lost at follow‐up did not differ on baseline characteristics compared with the remaining participants, neither across nor within conditions (all P > 0.05)."