Owen 1989.
Methods | Setting: community, Australia Recruitment: advertisements for smokers wishing to quit | |
Participants | 208 smokers; average age 42, average cpd 28 | |
Interventions | ∙ Quit Kit along with apology that course was full. Kit included a 5‐day cessation plan ∙ Self‐help programme in 4 mailed parts ∙ As in second bullet above, but personalised with additional text based on registration form (option to send for additional materials) | |
Outcomes | Abstinence at 9 months (point prevalence) Validation: some cotinine assays but no correction for a possible 15% misreport level | |
Notes | First intervention listed above meets criteria for basic self‐help, so 2 vs 1 for effect of additional materials and 3 vs 2 for effect of personalised materials | |
Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Unclear risk | Randomised; method not described |
Allocation concealment (selection bias) | Unclear risk | No details given |
Blinding (performance bias and detection bias) All outcomes | High risk | Control group (1) received notice that course was full; could introduce performance bias by artificially decreasing control group quit rates |
Incomplete outcome data (attrition bias) All outcomes | Unclear risk | 12% lost to follow‐up at 9 months; similar between groups Non‐respondents included as smokers |