Patten 2012.

Methods	Randomised controlled trial Study dates: Not stated Community volunteers, USA; random assignment
Participants	40 smokers, adolescent (supporter)‐parent dyads Parent: intervention group 40% male, mean age = 42.9 yrs, mean number of cigarettes smoked per day 20.7; control group 35% male, mean age = 42.6 yrs mean number of cigarettes smoked per day 19.9 Adolecent (supporter): intervention group 30% male, mean age 15.1 yrs; control group 30% male, mean age 15.2 yrs
Interventions	(1) Health education control group: a booklet related to health behaviour change for adolescent + 5 weekly 30‐minute counsellor‐facilitated group‐based sessions by an Internet chat room for giving general health information (n = 20) (2) Support skills training group: a booklet related to health behaviour change for adolescent + 5 weekly 30‐minute counsellor‐facilitated group‐based sessions by an Internet chat room for developing skills to support a parent to stop smoking (n = 20)
Outcomes	Self‐reported abstinence at 6 weeks and 6 months. Saliva cotinine samples collected at work, home, research site at 6 months. Adolescent Support Provided Measure and Parent Support Received Measure assessed
Notes	The study was not adequately powered to detect statistically significant group differences. Funded by an EAGLES Cancer Research Foundation grant. The EAGLES foundation had no role in the study design, collection, analysis or interpretation of data, writing of the manuscript or the decision to submit the paper for publication. Author declarations: "All authors declare they have no conflict of interest".
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Authors indicated participants were "randomly assigned". Method of sequence generation was not specified
Allocation concealment (selection bias)	Unclear risk	Method not specified
Blinding of outcome assessment (detection bias) All outcomes	Low risk	No blinding was reported, but the outcome was cotinine‐verified cessation
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "Ninety‐five percent (19 of 20) of adolescents in each study group completed the six‐month assessment. The six‐month assessment was completed by 85% of parents whose teen received HE and 90% of parents whose teen received SST". Parents lost to follow‐up counted as smokers in ITT analysis

CBT: cognitive behavioural therapy
 CO: carbon monoxide
 COPD: chronic obstructive pulmonary disease
 CVD: cardiovascular disease
 DOTS: Directly Observed Treatment for Tuberculosis Using A Short‐Course Regimen
 HMO: health maintenance organisation
 HSI: heaviness of smoking index
 HTN: hypertension
 m: month(s)
 MA: meta‐analysis
 NRT: nicotine replacement therapy
 PIQ: Partner Interaction Questionnaire
 PS: partner support
 TB: tuberculosis