Lichtenstein 2000.
Methods | Setting: community, USA Recruitment: via electric utility mailing to identify households with smokers and low radon concentrations | |
Participants | 1006 smokers in 714 households, average cpd 20 | |
Interventions | No face‐to‐face contact ∙ Standard Environmental Protection Agency leaflet on risks of radon ∙ Pamphlet highlighting risk of smoking in low concentrations of radon, with tips for quitting, or not smoking indoors ∙ Second bullet above plus up to 2 brief proactive telephone calls. All groups received standard letter with radon results | |
Outcomes | Abstinence at 12 months, sustained at 3 months and 12 months Validation: none | |
Notes | 2 vs 1, self‐help vs other control 3 contributes to telephone counselling review (Stead 2013b) Cluster‐randomisation; 54% of smokers lived with another smoker Intraclass correlation for sustained abstinence was .010; analyses did not correct for this |
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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 (performance bias and detection bias) All outcomes | Low risk | Self‐reported outcomes from participants not blinded to treatment condition, but the arms included in this analysis had similar levels of intensity with no personal contact, so differential misreport judged unlikely |
Incomplete outcome data (attrition bias) All outcomes | Low risk | 80% of households reached at 3 months and 12 months; no difference across conditions Missing treated as smoking |