Print-based self-help interventions for smoking cessation
© 2014 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. Background: Many smokers give up smoking on their own, but materials giving advice and information may help them and increase the number who quit successfully. Objectives: The aims of this review were to determine: the effectiveness of different forms of print-based self-help materials, compared with no treatment and with other minimal contact strategies; the effectiveness of adjuncts to print-based self help, such as computer-generated feedback, telephone hotlines and pharmacotherapy; and the effectiveness of approaches tailored to the individual compared with non-tailored materials. Search methods: We searched the Cochrane Tobacco Addiction Group trials register. Date of the most recent search April 2014. Selection criteria: We included randomized trials of smoking cessation with follow-up of at least six months, where at least one arm tested a print-based self-help intervention. We defined self help as structured programming for smokers trying to quit without intensive contact with a therapist. Data collection and analysis: We extracted data in duplicate on the participants, the nature of the self-help materials, the amount of face-to-face contact given to intervention and to control conditions, outcome measures, method of randomization, and completeness of follow-up. The main outcome measure was abstinence from smoking after at least six months follow-up in people smoking at baseline. We used the most rigorous definition of abstinence in each trial, and biochemically validated rates when available. Where appropriate, we performed meta-analysis using a fixed-effect model. Main results: We identified 74 trials which met the inclusion criteria. Many study reports did not include sufficient detail to judge risk of bias for some domains. Twenty-eight studies (38%) were judged at high risk of bias for one or more domains but the overall risk of bias across all included studies was judged to be moderate, and unlikely to alter the conclusions. Thirty-four trials evaluated the effect of standard, non-tailored self-help materials. Pooling 11 of these trials in which there was no face-to-face contact and provision of structured self-help materials was compared to no intervention gave an estimate of benefit that just reached statistical significance (n = 13,241, risk ratio [RR] 1.19, 95% confidence interval [CI] 1.04 to 1.37). This analysis excluded two trials with strongly positive outcomes that introduced significant heterogeneity. Six further trials without face-to-face contact in which the control group received alternative written materials did not show evidence for an effect of the smoking self-help materials (n = 7023, RR 0.88, 95% CI 0.74 to 1.04). When these two subgroups were pooled, there was no longer evidence for a benefit of standard structured materials (n = 20,264, RR 1.06, 95% CI 0.95 to 1.18). We failed to find evidence of benefit from providing standard self-help materials when there was brief contact with all participants (5 trials, n = 3866, RR 1.17, 95% CI 0.96 to 1.42), or face-to-face advice for all participants (11 trials, n = 5365, RR 0.97, 95% CI 0.80 to 1.18). Thirty-one trials offered materials tailored for the characteristics of individual smokers, with controls receiving either no materials, or stage matched or non-tailored materials. Most of the trials used more than one mailing. Pooling these showed a benefit of tailored materials (n = 40,890, RR 1.28, 95% CI 1.18 to 1.37) with moderate heterogeneity (I2 = 32%). The evidence is strongest for the subgroup of nine trials in which tailored materials were compared to no intervention (n = 13,437, RR 1.35, 95% CI 1.19 to 1.53), but also supports tailored materials as more helpful than standard materials. Part of this effect could be due to the additional contact or assessment required to obtain individual data, since the subgroup of 10 trials where the number of contacts was matched did not detect an effect (n = 11,024, RR 1.06, 95% CI 0.94 to 1.20). In two trials including a direct comparison between tailored materials and brief advice from a health care provider, there was no evidence of a difference, but confidence intervals were wide (n = 2992, RR 1.13, 95% CI 0.86 to 1.49). Only four studies evaluated self-help materials as an adjunct to nicotine replacement therapy, with no evidence of additional benefit (n = 2291, RR 1.05, 95% CI 0.88 to 1.25). A small number of other trials failed to detect benefits from using additional materials or targeted materials, or to find differences between different self-help programmes. Authors' conclusions: Standard, print-based self-help materials increase quit rates compared to no intervention, but the effect is likely to be small. We did not find evidence that they have an additional benefit when used alongside other interventions such as advice from a healthcare professional, or nicotine replacement therapy. There is evidence that materials that are tailored for individual smokers are more effective than non-tailored materials, although the absolute size of effect is still small. Available evidence tested self-help interventions in high income countries; further research is needed to investigate their effect in contexts where more intensive support is not available.