| Methods |
Setting: Community, USA
Recruitment: Active; by electric utility mailing with offer of radon test kit to identify households with smokers |
| Participants |
1364 households with 1821 smokers, ˜18 cigs/day |
| Interventions |
Factorial design crossing ± brief phone counselling with 15‐min video S‐H materials. All households given A Citizens Guide to Radon and letter tailored to results of radon level test
1. 1 ‐ 2 calls after receipt of radon test results. Clarified risk and encouraged quitting or no smoking in house. Second call scheduled if interested
2. No calls |
| Outcomes |
Self‐reported abstinence at 12 m (sustained at 3 and 12 m)
Validation: none |
| Notes |
Results of analyses accounting for clustering of multiple smokers in households reported to yield results generally consistent with simple analyses |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Responding households sequentially randomised to 4 conditions subject to stratification on radon test status |
| 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 |
83% of households completed 12 m assessment, 76% completed both 3 and 12 m |
