Nicholson 2015.

Methods	Country: USA Setting: hospital Type: RCT
Participants	119 parents or guardians of children receiving treatment for cancer who lived with at least 1 adult smoker and were exposed to SHS in the home or car setting
Interventions	Intervention: multi‐component behavioural programme over 3 months; counselling consisted of 3 individual, face‐to‐face, biweekly 1‐hour sessions followed by 3 25‐minute telephone sessions for a total of 6 individual contacts with the counsellor. Parents also received letters from their child's physician at the start and at the end of the counselling phase to acknowledge their participation and progress. Control: standard care and equivalent follow‐up to intervention arm
Outcomes	Child exposure (and target behaviour change): full smoking ban ‐ defined as a household with smokers that prohibited all smoking in the home and in the car
Type of intervention	Child with health problems (ill‐child health care)
Notes	Conflict of interest: none declared Source of funding: Grants CA085406 and CA21765 from the National Cancer Institute and the American Lebanese Associated Charities
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Stratified, blocked randomisation scheme with strata including child's age and race, as well as smoking status of the participating parent
Allocation concealment (selection bias)	Unclear risk	Not specified
Incomplete outcome data (attrition bias) All outcomes	Low risk	91% follow‐up rate
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not specified
Other bias	High risk	Reporting bias: smoking bans self‐reported, not validated biochemically