Table 6.
Results of reviews on smoking, ordered by type of control and further ordered by mode of delivery of intervention.
| Review | Relevant studies, n (total studies) | Method of synthesis | Interventions | Outcomes | Follow-up | Summary of findings | AMSTAR-2 rating | |
| Mixed (active and nonactive) controls | ||||||||
|
|
Afshin et al (2016) [99] | 22 (224) | Narrative synthesis of RCTsa and quasiexperimental studies | Internet and mobile interventions | Abstinence | 1 week-2 years | 77% (17/22) of studies reported a significant increase in abstinence. In studies reporting benefits, the ORb for 7-day abstinence at 6 months ranged from 1.6 (95% CI 1.1 to 2.4) to 2.7 (95% CI 1.8 to 4.0). | Critically low |
|
|
Boland et al (2016) [83] (Smoking only) | 13 (13) | Meta-analysis of RCTs | Various: website or computer program and SMS text messaging | Abstinence | 1 week-18 months | Interventions increased the odds of smoking cessation for disadvantaged groups at 1 month (OR 1.70; 95% CI 1.10 to 2.63), 3 months (OR 1.30; 95% CI 1.07 to 1.59), 6 months (OR 1.29, 95% CI 1.03 to 1.62) and 18 months postintervention (OR 1.83, 95% CI 1.11 to 3.01). | Low |
|
|
Aneni et al (2014) [100] | 3 (29) | Narrative synthesis of RCTs | Internet | Cessation | 12 months | 3 follow-up studies that measured smoking cessation showed significant intervention effects, although they were assessed to be of low quality. | Critically low |
|
|
Chebli et al (2016) [103] | 9 (16) | Narrative synthesis of RCTs | Internet | Cessation and reduction | 1-12 months | Internet-based interventions may have a positive effect on smoking cessation. Several studies found that web-based use and number of log-ins was positively associated with quit outcomes. | Critically low |
|
|
Cheung et al (2017) [85] (Smoking only) | 6 (45) | Narrative synthesis and meta-analysis of RCTs and quasi-RCTs | Internet | Cessation | >4 weeks | Only 13% (6/45) of studies provided data on effectiveness, with 66% (4/6) of studies demonstrating effectiveness. Smokers using a web-based cessation intervention were 1.15 to 2.84 times more likely to become a former smoker compared with the control condition (with a pooled RRc 1.39; 95% CI 1.18 to 1.65). | Critically low |
|
|
Gainsbury and Blaszczynski (2010) [87] (Smoking only) | 7 (9) | Narrative synthesis of RCTs and pre-experimental studies | Internet | Abstinence, tobacco use, smoking status, compliance, nicotine dependence, carbon monoxide markers, and toxicity | 3-12 months | 86% (6/7) of studies reported significantly greater self-reported smoking quit rates or abstinence at the end of the treatment trial for participants in the internet intervention compared with controls. Several trials found improvements at 3, 6, and 12 months. | Critically low |
|
|
Graham et al (2016) [88] (Smoking only) | 40 (40) | Meta-analysis of RCTs | Internet | Abstinence | 7 days-3 months | Pooled results from 15 trials (24 comparisons) found a significant effect in favor of experimental internet interventions (RR 1.16; 95% CI 1.03 to 1.31; I2=76.7%). | Critically low |
|
|
Hutton et al (2011) [90] (Smoking only) | 15 (21) | Narrative synthesis of RCTs | Internet | Cessation | >1 month | Two RCTs found that a multicomponent intervention with web and nonweb-based elements was more efficacious than a self-help manual, and one of the 2 RCTs found that web-based interventions may be more effective than no treatment. Three trials provided insufficient evidence to demonstrate whether web-based interventions were more efficacious than counselling. Tailored websites in 2 RCTs and greater website exposure in 86% (6/7) of RCTs were associated with higher rates of abstinence. | Critically low |
|
|
Lustria et al (2013) [110] | 8 (40) | Meta-analysis of experimental and quasiexperimental studies | Internet | Abstinence | 30 days-6 months | Web‐based, tailored interventions had significantly greater improvement in smoking outcomes compared with control conditions, with small effects, Cohen d=0.151 (k=8; 95% CI 0.11 to 0.19; P<.001). | Critically low |
|
|
McCrabb et al (2019) [91] (Smoking only) | 45 (45) | Meta-analysis of RCTs | Internet | Abstinence | 1-18 months | Interventions were effective in the short term (OR 1.29, 95% CI 1.12 to 1.50; P=.001) and long term (OR 1.1.9, 95% CI 1.06 to 1.35; P=.004). | Low |
|
|
Shahab and McEwen (2009) [95] (Smoking only) | 10 (11) | Meta-analysis of RCTs | Internet | Cessation | >1 month | Interactive interventions were effective compared with untailored booklets or emails (RR 1.8; 95% CI 1.4 to 2.3) increasing 6-month abstinence by 17% (95% CI 12 to 21%); no evidence was found of a difference between interactive and static interventions. | Critically low |
|
|
Taylor et al (2017) [97] (Smoking only) | 61 (67) | Meta-analysis of RCTs and quasi-RCTs | Internet | Cessation | 6-12 months | Interactive and tailored internet-based interventions with or without additional behavioral support are moderately more effective than nonactive controls at 6 months or longer, but there was no evidence that these interventions were better than other active smoking treatments. | Moderate |
|
|
Webb et al (2010) [113] | 12 (85) | Meta-analysis of RCTs | Internet | Smoking abstinence | 12 months | Interventions that targeted smoking abstinence tended to have small effects on behavior that did not reach statistical significance (Cohen d+=0.07; k=12; 95% CI −0.04 to 0.18). | Critically low |
|
|
Head et al (2013) [107] | 5 (19) | Meta-analysis of RCTs | SMS text messaging | Smoking cessation | Mean 81.26 days | The weighted mean effect size for smoking cessation, Cohen d=0.447 (95% CI .367 to .526; P=.001; k=5). | Critically low |
|
|
Scott-Sheldon et al (2016) [94] (smoking only) | 18 (20) | Meta-analysis of RCTs | SMS text messaging | Abstinence, cigarette use, quit attempts, and nicotine dependence | Not reported | SMS text messaging was associated with significantly greater odds of abstinence compared with controls: 7-day point prevalence (OR 1.38, 95% CI 1.22 to 1.55; k=16) and continuous abstinence (OR 1.63, 95% CI 1.19 to 2.24; k=7); interventions were also more successful in reducing cigarette consumption (Cohen d+=0.14; 95% CI 0.05 to 0.23; k=9). | Critically low |
|
|
Spohr et al (2015) [96] (smoking only) | 10 (13) | Meta-analysis of RCTs | SMS text messaging | Cessation | 3 and 6 months | Interventions generally increased quit rates compared with controls (OR 1.36, 95% CI 1.23 to 1.51). Intervention efficacy was higher in studies with a 3-month follow-up compared with a 6-month follow-up. | Critically low |
|
|
Palmer et al (2018) [111] | 18 (71) | Meta-analysis of RCTs | Mobile | Abstinence and cessation (verified biochemically) | 24 hours-6 months | The effect of SMS text messaging–based smoking cessation support on biochemically verified continuous abstinence was pooled relative risk, RR 2.19 (95% CI 1.80 to 2.68; I2=0%) and on verified 7-day point prevalence of smoking cessation was pooled RR 1.51 (95% CI 1.06 to 2.15; I2=0%). | Moderate |
|
|
Whittaker et al (2016) [98] (smoking only) | 12 (12) | Meta-analysis of RCTs and quasi-RCTs | Mobile | Cessation | 6 months | Smokers who received support programs were 1.7 times more likely to stay quit than smokers who did not receive the programs (9.3% quit with programs compared with 5.6% who quit with no programs). Most of the studies were of programs relying mainly on text messages. | Moderate |
|
|
Danielsson et al (2014) [86] (smoking only) | 21 (74) | Narrative synthesis of RCTs | Various | Abstinence | >3 months | The studies showed mixed results regarding internet interventions and smoking, with some positive effects for the smoking cessation program that combined the use of both the internet, mobile phones (SMS text messaging), and email. | Critically low |
|
|
HIQA (2017) [89] (smoking only) | 12 (143)d | Network meta-analyses of RCTs | Various: internet and mobile | Cessation | 6-12 months | Internet-based interventions are superior to control (brief advice or written materials; RR 1.43, 95% CI 1.02 to 2.00; P=.04; k=5); Internet-based interventions are superior to doing nothing (RR 1.46, 95% CI 1.18 to 1.81; P<.001; k=3); mobile phone–based interventions appear to have similar effectiveness to control (RR 1.18, 95% CI 0.88 to 1.60; P=.27; k=3); no evidence of difference between mobile phone–based interventions and internet (RR 1.43, 95% CI 0.88 to 2.31; P=.15; k=1). | Low |
|
|
Hou et al (2013) [108] | 5 (38) | Narrative synthesis of studies with comparison or control groups | Web-based computer programs | Cessation | Not reported | 2 studies found higher cessation rates in intervention groups than control. 3 studies found no significant differences in quit rates at the end of the intervention or at follow-ups. | Critically low |
|
|
Myung et al (2009) [92] (smoking only) | 22 (22) | Meta-analysis of RCTs | Various: internet or computer based | Abstinence and biochemical markers | >3 months | Intervention groups had a significant effect on smoking cessation (RR 1.44; 95% CI 1.27 to 1.64). Similar findings were observed in web-based interventions (RR 1.40; 95% CI 1.13 to 1.72) and in computer-based interventions (RR 1.48; 95% CI 1.25 to 1.76). | Critically low |
|
|
Naslund et al (2017) [93] (smoking only) | 7 (7) | Narrative synthesis of all study types | Social media | Cessation | 30-365 days | 71% (5/7) of studies reported significant effects on smoking-related outcomes such as greater abstinence, reduction in relapse, and an increase in quit attempts. | Critically low |
|
|
Elaheebocus et al (2018) [56] | 7 (134) | Narrative synthesis of RCTs | Social media | Cessation | 6-48 months | 100% (7/7) of studies on smoking cessation using web-based social networks had positive results. | Critically low |
|
|
Rooke et al (2010) [112] | 13 (34) | Meta-analysis of RCTs | Computer based | Abstinence and reduction | 1-156 weeks | The weighted average effect size (Cohen d) was 0.14; P<.001 for studies addressing tobacco use. | Critically low |
| Nonactive controls | ||||||||
|
|
Chen et al (2012) [84] (smoking only) | 60 (60) | Meta-analysis of RCTs and quasi-RCTs | Various: computer and other electronic aids | Cessation | 2 days-30 months | Computer and other electronic aids increase the likelihood of cessation compared with no intervention or generic self-help materials but the effect is small (prolonged abstinence: RR 1.32; 95% CI 1.21 to 1.45). | Low |
|
|
Krebs et al (2010) [109] | 32 (88) | Meta-analysis of RCTs | Computer tailored | Abstinence | 24 hours-9 months | Mean effect for the 32 studies reporting point prevalence outcome was g=0.16 (95% CI 0.12 to 0.19); mean effect for the 16 studies reporting prolonged abstinence measures was g=0.24 (95% CI 0.20 to 0.31). | Low |
| Active controls | ||||||||
|
|
Covolo et al (2017) [104] | 2 (40) | Narrative synthesis of RCTs | Mobile apps | 30-day point prevalence cessation | 30 days | 1 trial compared 2 apps and found no evidence of any difference; the other found text messaging produced more abstinence than an app (P<.05). |
Critically low |
aRCT: randomized controlled trial.
bOR: odds ratio.
cRR: risk ratio.
dIn total, 12 relevant studies were included in the meta-analysis.