Borrelli 2016.

Methods	Country: USA Setting: community (home and telephone) Type: RCT
Participants	560 smoking primary caregivers (parents) of both children with asthma and healthy children
Interventions	• Precaution adoption model intervention (PAM; motivational interviewing to deliver feedback on child's second‐hand smoke (SHS) exposure and smokers' carbon monoxide levels and cessation induction strategies). • Home visit (for aim 1/teachable moment): Parents of children with asthma received NIH guideline‐based asthma education, while parents of healthy children received child wellness counselling. All participants received identical smoking cessation counselling via motivational interviewing. Verbal and graphical feedback was provided regarding smoking level, carbon monoxide level, how quitting could reduce disease risk and symptoms, the child's SHS exposure, risk of smoking on the child's SHS exposure, and how risks could be reduced by quitting smoking or reducing SHS exposure. • Telephone counselling (for aim 2/intervention intensity): Both PAM and enhanced PAM received six 15‐ to 20‐minute calls regarding asthma symptoms and management for 4 months after the home visits. Enhanced PAM also received smoking cessation and a second round of SHS exposure feedback.
Outcomes	Child exposure: 2 passive nicotine monitors (dosimetry) placed for 1 week during each of the 2 measurement periods (baseline and after call 5) ‐ 1 in the room where the child spends the most time and 1 worn by the child. Parent‐reported SHS exposure assessed by structured interview Child illness: asthma morbidity (numbers of asthma‐related hospitalisations, school days missed due to asthma, days with asthma symptoms, and Asthma Functional Morbidity Scale scores) Child health service utilisation: asthma‐related hospitalisations Target behaviour change: proportion of participants who quit; verified by expired air carbon monoxide testing at all follow‐up intervals
Type of intervention	Child with health problems (respiratory disorders)
Notes	Conflict of interest: none declared Source of funding: NIH grant R01 HL062165‐06
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Urn randomisation (form of adaptive biased‐coin randomisation)
Allocation concealment (selection bias)	Low risk	Allocation sequence could not be accessed by staff.
Incomplete outcome data (attrition bias) All outcomes	High risk	Although no significant difference was seen in the counselling call completion rate, this rate was only 55% by 12‐month follow‐up.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Objective measure used ‐ air nicotine
Other bias	High risk	• At baseline, comparison group (healthy children) was significantly different from the 2 intervention groups (PAM and enhanced PAM) with respect to child and parent age, cigarettes smoked per day, years smoked, nicotine dependence, and % household smoking ban. Note that randomisation only occurred for the 2 intervention arms. • Potential detection bias in that the half‐life of carbon monoxide is 4 to 6 hours, and so 7‐ and 30‐day point prevalence abstinence cannot be verified beyond that time frame.