Curry 1995.
Methods | Setting: HMO, USA Recruitment: smokers identified via a telephone survey of health behaviour in a random sample of HMO members (unselected) | |
Participants | 1137 smokers, 53% female, average age 41, average cpd 17 | |
Interventions | No face‐to‐face contact ∙ Control ‐ no materials ∙ Self‐help booklet (Breaking Away) with units to complete, relevant to all stages of readiness to quit ∙ As second bullet above plus feedback based on computer analysis of initial survey; included a handwritten form and a list of relevant parts of booklet ∙ As third bullet above plus up to 3 counsellor‐initiated phone calls (not included in this review) | |
Outcomes | Sustained abstinence 3 months to 12 months Validation: saliva cotinine requested but not obtained for all participants; disconfirmation rates not significantly different between groups | |
Notes | 12 months' rather than 21 months' follow‐up used for comparability with other studies; study author confirmed numbers quit
2 vs 1 in self‐help vs control 3 vs 2 in effects of tailoring |
|
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 aware that they may be receiving materials or phone calls, which they did not receive; this could introduce performance bias "Collecting saliva cotinine...was challenging because participants had neither explicitly volunteered for a study of smoking behavior nor requested treatment for smoking cessation... nearly one fourth of those contacted refused to provide a sample" Higher disconfirmation in control group but difference not significant |
Incomplete outcome data (attrition bias) All outcomes | Low risk | 88% provided data at 3 months and at 12 months No difference in response rates across groups Missing counted as smoking in meta‐analysis |