| Methods |
Setting: Community, USA
Recruitment: Active; by electric utility mailing to identify households with smokers and low radon concentrations |
| Participants |
1006 smokers in 714 households (651 in relevant arms); av. cigs/day 20 |
| Interventions |
1. Standard Environmental Protection Agency leaflet on risks of radon (this arm not used in review)
2. Pamphlet highlighting risk of smoking in low concentrations of radon, with tips for quitting, or not smoking indoors
3. Pamphlet as 2, plus up to 2 brief (mean about 6 mins) proactive TC sessions |
| Outcomes |
Self‐reported abstinence at 12 m (sustained at 3 and 12 m)
Validation: none |
| Notes |
Arms 3 vs 2, effect of TC versus S‐H alone
Cluster‐randomisation, 54% of smokers lived with another smoker. Intraclass correlation coefficient for sustained abstinence was .010. Analyses did not correct for this. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Randomised by household, method not described |
| Allocation concealment (selection bias) |
Unclear risk |
No details given |
| Blinding of outcome assessment (detection bias)
All outcomes |
High risk |
Self‐reported outcomes from participants not blinded to treatment condition. Level of personal contact differed between arms |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
80% of households reached at 3 and 12 m, no difference across conditions. Missing treated as smoking |
