Table 2 Inclusion and exclusion criteria

1. Not in English language

We excluded all papers not in English because of lack of translation facilities.

2. Type of study

Randomised controlled trials (RCTs), controlled non-randomised studies and controlled before and after studies. Comparison groups of the family intervention could be usual care, no intervention or another smoking cessation intervention. Feasibility and pilot studies were included if effects of the intervention were reported.

3. Type of intervention

Interventions promoting changes in adult tobacco use or prevention. Interventions involving at least one family member. Interventions that gave the option of including a family member or close friend/significant other were excluded. Interventions where the primary aim was to reduce exposure to secondhand smoke and place of smoking were excluded. Interventions delivered to whole-community or whole-population level interventions such as media campaigns or changes in the local environment, which included a discrete family-based intervention, were included.

4. Type of participants

The target of the intervention was an adult of any gender who smoked (18 years and over). One or more of the adult smoker’s family had to be involved in the intervention. Pregnant and non-pregnant and married and unmarried smokers were included. Interventions that targeted adults and children who smoked were included but only if outcomes of adults were reported separately and only if the intervention specifically targeted adult smoking behaviour. Interventions that only targeted children’s smoking behaviour were excluded.

5. Type of outcomes

Outcomes were the change in number of cigarettes smoked/smoking cessation of adults. Behaviours could be measured objectively (e.g., saliva) or by self-report questionnaire. If it was a multi-component intervention (e.g., family-based programme administered as part of a school-based programme to prevent smoking up-take in young people) then the effects of the family-based programme of the intervention must have been reported separately. Studies that aimed to shift location of smoking behaviour and reduce Environmental Tobacco Smoke as opposed to smoking cessation were excluded.