Walker 2015.

Methods	Country: Australia and New Zealand Setting: community (home) Type: RCT
Participants	293 mothers of infants between birth and 5 weeks of age, when mothers self‐identified as Maori or Australian Aboriginal/Torres Strait Islander and mothers were current smokers, or the infant lived in a household with at least 1 smoker
Interventions	Intervention: Mothers (and family members present) received usual care plus behavioural coaching about dangers of SHS exposure to children, commitment to smoking restrictions in the home/car, positive role modelling, and strategies for overcoming obstacles to making smoke‐free changes. Smokers also were offered brief advice or intensive counselling to quit and were offered free NRT and/or a quit line referral. Control: usual care, which included brief quit advice and the provision of smoking cessation treatment
Outcomes	Child exposure: child urine cotinine, self‐report smoking restrictions in home/car, self‐reported SHS exposure, and self‐reported smoking cessation Child illness: parent‐reported cough in child Child health service utilisation: rate of health provider presentations and/or hospitalisations for new primary episodes of acute respiratory illness in the first year of life Target behavioural change: smoking cessation, restriction, and home/car smoking ban
Type of intervention	Community‐based
Notes	Conflicts of interest: All authors declare that (1) no trial authors have received support from any companies for the submitted work; (2) CB has previously undertaken research on behalf of NicoNovum, but before the purchase of the company by RJ Reynolds. NW has provided consultancy to the manufacturers of smoking cessation medications, received honoraria for speaking at a research meeting, and received benefits in kind and travel support from a manufacturer of smoking cessation medications. MG has provided consultancy to the manufacturers of smoking cessation medications; (3) their spouses, partners, or children have no financial relationships that may be relevant to the submitted work; and (4) all trial authors have no non‐financial interests that may be relevant to the submitted work. NW, CB, MG, and VP have also undertaken 2 trials of very low nicotine content cigarettes, which were purchased from 2 different tobacco companies. The companies concerned had no role in development of the study design, data collection, data analysis, data interpretation, or writing of the trial publications. Source of funding: National Health and Medical Research Council of Australia (545203); the Health Research Council of NZ (09/626); Cure Kids NZ (3525); and the James Russell Lewis Trust, New Zealand (13787/15734)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomised in a 1:1 ratio to 1 of 2 arms by central computer using block randomisation stratified by country
Allocation concealment (selection bias)	Low risk	Not specified, but allocation was randomised by a central computer
Incomplete outcome data (attrition bias) All outcomes	Low risk	88% follow‐up in intervention group and 86% follow‐up in control group
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Objective measure and single‐blind (research staff assessing the primary outcome were blinded to treatment allocation)