© 2019 The Cochrane Collaboration. Background: Many smokers give up smoking on their own, but materials that provide a structured programme for smokers to follow may 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 that provide a structured programme for smokers to follow, compared with no treatment and with other minimal contact strategies, and to determine the comparative effectiveness of different components and characteristics of print-based self-help, such as computer-generated feedback, additional materials, tailoring of materials to individuals, and targeting of materials at specific groups. Search methods: We searched the Cochrane Tobacco Addiction Group Trials Register, ClinicalTrials.gov, and the International Clinical Trials Registry Platform (ICTRP). The date of the most recent search was March 2018. Selection criteria: We included randomised trials of smoking cessation with follow-up of at least six months, where at least one arm tested print-based materials providing self-help compared with minimal print-based self-help (such as a short leaflet) or a lower-intensity control. 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 accordance with standard methodological procedures set out by Cochrane. 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 study and biochemically validated rates when available. Where appropriate, we performed meta-analysis using a random-effects model. Main results: We identified 75 studies that met our inclusion criteria. Many study reports did not include sufficient detail to allow judgement of risk of bias for some domains. We judged 30 studies (40%) to be at high risk of bias for one or more domains. Thirty-five studies evaluated the effects of standard, non-tailored self-help materials. Eleven studies compared self-help materials alone with no intervention and found a small effect in favour of the intervention (n = 13,241; risk ratio (RR) 1.19, 95% confidence interval (CI) 1.03 to 1.37; I2 = 0%). We judged the evidence to be of moderate certainty in accordance with GRADE, downgraded for indirect relevance to populations in low- and middle-income countries because evidence for this comparison came from studies conducted solely in high-income countries and there is reason to believe the intervention might work differently in low- and middle-income countries. This analysis excluded two studies by the same author team with strongly positive outcomes that were clear outliers and introduced significant heterogeneity. Six further studies of structured self-help compared with brief leaflets did not show evidence of an effect of self-help materials on smoking cessation (n = 7023; RR 0.87, 95% CI 0.71 to 1.07; I2 = 21%). We found evidence of benefit from standard self-help materials when there was brief contact that did not include smoking cessation advice (4 studies; n = 2822; RR 1.39, 95% CI 1.03 to 1.88; I2 = 0%), but not when self-help was provided as an adjunct to face-to-face smoking cessation advice for all participants (11 studies; n = 5365; RR 0.99, 95% CI 0.76 to 1.28; I2 = 32%). Thirty-two studies tested materials tailored for the characteristics of individual smokers, with controls receiving no materials, or stage-matched or non-tailored materials. Most of these studies used more than one mailing. Pooling studies that compared tailored self-help with no self-help, either on its own or compared with advice, or as an adjunct to advice, showed a benefit of providing tailored self-help interventions (12 studies; n = 19,190; RR 1.34, 95% CI 1.20 to 1.49; I2 = 0%) with little evidence of difference between subgroups (10 studies compared tailored with no materials, n = 14,359; RR 1.34, 95% CI 1.19 to 1.51; I2 = 0%; two studies compared tailored materials with brief advice, n = 2992; RR 1.13, 95% CI 0.86 to 1.49; I2 = 0%; and two studies evaluated tailored materials as an adjunct to brief advice, n = 1839; RR 1.72, 95% CI 1.17 to 2.53; I2 = 10%). When studies compared tailored self-help with non-tailored self-help, results favoured tailored interventions when the tailored interventions involved more mailings than the non-tailored interventions (9 studies; n = 14,166; RR 1.42, 95% CI 1.20 to 1.68; I2 = 0%), but not when the two conditions were contact-matched (10 studies; n = 11,024; RR 1.07, 95% CI 0.89 to 1.30; I2 = 50%). We judged the evidence to be of moderate certainty in accordance with GRADE, downgraded for risk of bias. Five studies evaluated self-help materials as an adjunct to nicotine replacement therapy; pooling three of these provided no evidence of additional benefit (n = 1769; RR 1.05, 95% CI 0.86 to 1.30; I2 = 0%). Four studies evaluating additional written materials favoured the intervention, but the lower confidence interval crossed the line of no effect (RR 1.20, 95% CI 0.91 to 1.58; I2 = 73%). A small number of other studies did not detect benefit from using targeted materials, or find differences between different self-help programmes. Authors' conclusions: Moderate-certainty evidence shows that when no other support is available, written self-help materials help more people to stop smoking than no intervention. No evidence shows that when people receive advice from a health professional or are using nicotine replacement therapy, self-help materials add to the effects of these approaches. However, small benefits cannot be excluded. Moderate-certainty evidence shows that self-help materials that use data from participants to tailor the nature of the advice or support given are more effective than no intervention. However, when researchers compared tailored self-help materials, which typically involve repeated assessment and mailing, versus untailored materials delivered similarly, they noted no benefit. Available evidence was obtained when investigators tested self-help interventions in high-income countries, where more intensive support is often available. Further research is needed to investigate effects of these interventions in low- and middle-income countries, where more intensive support may not be available.
Cochrane Database of Systematic Reviews