Which eHealth interventions are most effective for smoking cessation? A systematic review

Figures & data

Table 1 “Textword” searches

Topic	Key terms
Smoking	Tobacco, smok*, cigarette
Device	Mobile phone, smartphone, smart-phone, computer, tablet, handheld, cellular phone, cell phone
eHealth	Online, mobile, technology, electronic health, eHealth, chat room, social media, mobile application, mobile health application, mhealth, text messaging, telemedicine, internet, multimedia, web, electronic mail, e-mail
Intervention	Intervent*, prevent*, trial, campaign

Abbreviations: eHealth, electronic health; mHealth, mobile health.

Table 2 Subgroups of effect modifiers employed in the meta-analysis and meta-regression

Effect modifiers	Subgroup
Follow-up time- points	1. <6 months of follow-up – short-term abstinence
	2. ≥6 months of follow-up – long-term abstinence
Effective public health practice project ranking	1. Weak quality (high risk of bias)
	2. Moderate quality (moderate risk of bias)
	3. Strong quality (low risk of bias)
Target population	1. Adult smokers
	2. Youths
	3. Other vulnerable subjects (chronic patients, pregnant women, and so on)
Tailored intervention	1. Tailored intervention
	2. Untailored intervention
Interactive intervention	1. Interactive
	2. Noninteractive
Frequency of text message	1. High frequency
	2. Low frequency
Control characteristics	1. Nonactive control group
	2. Active control group
	3. Other eHealth platforms
Location of trials	1. Developed countries (USA, EU)
	2. Less developed countries (rest of the world)
Theory-based intervention	1. Yes
	2. No
Clinician contact	1. Yes
	2. No

Abbreviation: eHealth, electronic health; EU, European Union.

Figure 1 PRISMA diagram of searching and screening process.

Abbreviation: eHealth, electronic health; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Table 3 General characteristics of included studies (n=91)

Characteristics	N	%
Publication year
• 2010 to Feb 2017	74	68.52
• 2000–2009	33	30.56
• 1999	1	0.93
Study designs
• Randomized control trial	105	97.22
• Quasi-experiment	2	1.85
• Controlled before–after studies	1	0.93
Intervention
• Web-based	67	62.04
• Computer-based	13	12.04
• mHealth (SMS, apps)	24	22.22
• Others (social media, chat-room, and other electronic aids)	4	3.70
Settings
• USA	58	53.70
• Europe	41	37.96
• Australia and New Zealand	6	5.56
• Asia	3	2.78
Participants
• Adults	64	59.26
• Youth (from 15 to 24 years old)	26	24.07
• Patients with chronic disease, pregnant women	18	16.67
Multiple eHealth platforms
• Single eHealth platform	43	40
• Multiple eHealth platforms	32	30
• Combined with non-eHealth platform	23	21
• Combined with financial incentives	4	4
Theoretical framework
• Transtheoretical model	25	23.15
• Cognitive-behavioral therapy	16	14.81
• Social cognitive theory	11	10.19
• Multitheories	20	18.52
• Not available	18	16.67
• Others	18	16.67
Method to confirm smoking status
• Self-report	74	68.52
• Biochemically validation (CO breath test or	34	31.48
urine test)
Length of follow-up
• From 1 to <6 months	32	29.63
• From 6 to 12 months	48	44.44
• More than 12 months	28	25.93

Abbreviations: CO, exhaled carbon monoxide; eHealth, electronic health; mHealth, mobile health.

Figure 2 Risk of bias graph based on review authors’ judgments across all included studies.

Figure 3 Forest plot of web based intervention effects by characteristics of control group.

Abbreviations: M–H, Mantel–Haenszel; NRT, nicotine replacement therapy.

Figure 4 Forest plot of mHealth intervention effects by characteristics of control group.

Abbreviations: eHealth, electronic health; M–H, Mantel–Haenszel; mHealth, mobile health.

Figure 5 Forest plot of computer-assisted intervention effects by characteristics of control group.

Abbreviation: M–H, Mantel–Haenszel.

Table 4 Summary of findings on effects of eHealth smoking cessation interventions, based on GRADE guidelines

Outcome, follow-up	Summary of the effect (95% CI)	Number of participants and studies	Quality of the evidence (GRADE)	Summary for intervention
Web-based smoking cessation interventions
Web-based vs nonactive control
Cessation, >6 months	RR 1.06 (0.99–1.16)	11,344;	⊕⊕⊕⊖a	Probably little or no increase upon cessation
	Little or no increase	11 studies	Moderate
Cessation, 6 months	RR 2.03 (1.7–2.03)	5,560;	⊕⊕⊖⊖b	May increase cessation
	Important increase	7 studies	Low
Cessation, 1–6 months	RR 1.21 (1.08–1.36)	11,078;	⊕⊕⊕⊖a	Probably increases cessation slightly
	Moderate increase	5 studies	Moderate
Tailored web-based vs untailored control group
Cessation, any follow-up	1.09 (1.02–1.17)	23,493;	⊕⊕⊕⊖a	Probably little or no increase upon cessation
	Little or no increase	18 studies	Moderate
Web-based vs control group, both groups received NRT/counseling
Cessation, any follow-up	1.29 (1.17–1.43)	3,619;	⊕⊕⊕⊖a	Probably increases cessation slightly
	Moderate increase	11 studies	Moderate
Web-based vs other eHealth modes for cessation outcome
Cessation, any follow-up	1.03 (0.94–1.13)	15,568;	⊕⊕⊕⊖a	Probably little or no increase upon cessation
	Little or no increase	8 studies	Moderate
mHealth smoking cessation interventions
mHealth vs nonactive control
Cessation, any follow-up	1.71 (1.35–2.16)	2,942;	⊕⊕⊖⊖b	May increase cessation
	Important increase	9 studies	Low
High-frequency vs low-frequency SMS
Cessation, any follow-up	1.08 (1.02–1.15)	11,376;	⊕⊕⊖⊖a,c	May make little or no difference upon cessation
	Little or no increase	4 studies	Low
mHealth vs other eHealth modes
Cessation, any follow-up	1.35 (1.04–1.75)	2,389;	⊕⊕⊖⊖a,d	May increase cessation slightly
	Moderate increase	4 studies	Low
Tailored SMS vs nonsmoking/untailored SMS
Cessation, any follow-up	1.80 (1.54–2.10)	8,147;	⊕⊕⊖⊖a,c	May increase cessation
	Important increase	6 studies	Low
Computer-assisted smoking cessation intervention
Computer-based vs usual care
Cessation, any follow-up	1.16 (1.06–1.26)	1,703;	⊕⊕⊖⊖b	May make little or no increase upon cessation
	Little or no increase	9 studies	Low
Computer-based vs active control
Cessation, any follow-up	1.31 (1.11–1.53)	13,435;	⊕⊕⊖⊖b	May increase cessation slightly
	Moderate increase	5 studies	Low

Notes: Reasons for downgrading of quality:

a downgraded 1 level for significant risk of bias;

b downgraded 2 levels for serious risk of bias;

c downgraded 1 level of inconsistency;

d downgraded 1 level for imprecision. GRADE Working Group grades of evidence. ⊕⊕⊕⊕High quality: Further research is very unlikely to change our confidence in the estimate of effect. ⊕⊕⊕⊖Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. ⊕⊕⊖⊖Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.

Abbreviations: eHealth, electronic health; GRADE, Grading of Recommendations Assessment, Development and Evaluation; mHealth, mobile health; NRT, nicotine replacement therapy; RR, risk ratio.

Table 5 Core effect modifier using meta-regression, stratified by eHealth platforms

Covariates	Treatment effect Log RR (95% CI)	P-value
Web-based (n=58)
EPHPP ranking (weak–moderate–strong)	−0.146 (−0.250 to −0.041)	0.006
Interactive intervention (yes vs no)	0.030 (−0.120 to 0.179)	0.696
Tailored intervention (yes vs no)	−0.087 (−0.239 to 0.064)	0.259
Theory-based intervention (yes vs no)	−0.106 (−0.266 to 0.054)	0.196
Computer-assisted (n=14)
EPHPP ranking (weak–moderate–strong)	0.074 (−0.101 to 0.248)	0.407
Interactive intervention (yes vs no)	0.119 (−0.047 to 0.285)	0.16
Tailored intervention (yes vs no)	0.160 (−0.095 to 0.416)	0.219
Theory-based intervention (yes vs no)	−0.244 (−0.865 to 0.376)	0.440
Clinician contact (yes vs no)	0.086 (−0.169 to −0.341)	0.509
mHealth (n=21)
EPHPP ranking (weak–moderate–strong)	0.403 (0.221 to 0.584)	0.001
Interactive intervention (yes vs no)	−0.218 (−0.471 to 0.034)	0.09
Tailored intervention (yes vs no)	0.450 (0.185 to 0.714)	0.001
Frequent messages (high vs low)	−0.224 (−0.606 to −0.359)	0.025
Location of trial (less developed vs developed countries)	−0.483 (−0.606 to −0.359)	0.001

Note: The values in bold indicate P<0.05 (statistically significant value).

Abbreviations: eHealth, electronic health; EPHPP, Effective Public Health Practice Project; mHealth, mobile health; RR, risk ratio.