This study conducted a meta-analysis of five randomized controlled trials testing the effectiveness of mobile phone-based smoking cessation interventions in different countries. The analysis found that mobile phone interventions significantly increased self-reported quit rates at 4 weeks, with 28.6% of the intervention group reporting quitting compared to 12.3% of the control group. A strong treatment effect was also observed at 3 months, though this was reduced. At 6 months, the intervention significantly increased continuous abstinence rates. The results suggest mobile phone programs can consistently and effectively help people quit smoking across different cultures.

1. Table 3. Self-reported quitting at 4 weeks
Odds Ratio Relative Risk
Estimate 95%
Lower
CI
95%
Upper
CI
P-value Estimate 95%
Lower
CI
95%
Upper
CI
P-value
Overall 2.89 2.57 3.26 < 0.0001 2.34 2.12 2.58 < 0.0001
STOMP 3.04 2.25 4.09 < 0.0001 2.45 1.92 3.13 < 0.0001
TEXT2STOP 3.02 2.62 3.47 < 0.0001 2.43 2.17 2.73 < 0.0001
TEXT2QUIT 2.63 1.68 4.12 < 0.0001 2.12 1.48 3.03 < 0.0001
SMS USA 2.22 1.09 4.53 0.0278 1.52 0.96 2.42 0.0762
SMS TURKEY 1.00 0.40 2.48 0.9996 0.97 0.48 1.99 0.9415
A strong but reduced treatment effect was observed at 3 months (adjusted OR 1.88, 95% CI
1.53-2.31; p-value<.0001), using the data collected in four studies (Figure 1).The proportion
of smokers who self-reported quitting was 29.4% in the intervention group (n=380/1291),
compared with 18.8% in the control group (n=231/1232).
Figure 1. Self-reported quitting at 3 months
Trials
TEXT2Quit
STOMP
SMS_USA
SMS_TURKEY
Overall
Favours Control
Odds Ratio 95% CI
Favours Intervention
71 3 5
At 6 months (Figure 2), only two studies evaluated continuous abstinence since their quit day,
both of which found significant intervention effects on quitting.The proportion of smokers who
self-reported quitting was 13.1% in the intervention group (n=493/3763), compared with 6.4%
in the control group (n=237/3734).The adjusted odds ratio was 2.24 (95% CI 1.90-2.64; p-value
<.0001). Older people and those with a lower Fagerstrom score were more likely to successfully
quit. No association was found with other confounders.
Figure 2. Self-reported continuous abstinence at 6 months
Trials
STOMP
TEXT2STOP
Overall
Favours Control
21 3
Odds Ratio 95% CI
Favours Intervention
At all visits, no significant interactions with the intervention were found with participants’ sex
and level of nicotine dependence.
Conclusions
Data from across four countries and a diversity of cultures suggest that mobile phone-based
smoking cessation programs have a consistent effect at increasing the chance of quitting. Further
research is needed to evaluate the potential impact of different frequencies and intensities of the
intervention on the size of overall treatment effect.
Yannan Jiang1,5
, Ying Huang1,5
, Michele Ybarra2
, Lorien Abroms3
, Caroline Free4
, Robyn Whittaker5
1
The University of Auckland, Auckland, New Zealand • 2
Center for Innovative Pubic Health, San Clemente, United States
3
George Washington University, Washington D.C., United States • 4
London School of Hygiene & Tropical Medicine, London, United Kingdom
5
National Institute for Health Innovation, Auckland, New Zealand
Meta-Analysis of Mobile Phone-based Interventions
for Smoking Cessation Trials in Different Countries
Introduction
Tobacco use contributes to 12% of all deaths among adults ages 30 years and older worldwide.
Smoking cessation programs delivered via mobile phone text messaging are available in several
different countries to help people quit smoking.Although results suggest increases in self-
reported quitting, at least in the short-term, little is known about how this differs for different
cultures.
Methods
Individual participants’ data (N=8,315) collected in five randomised control trials in New Zealand,
UK, USA and Turkey were included for meta-analysis. Frequency and intensity of intervention
strategies and outcome assessments were compared.The primary outcome was self-reported
seven-day point prevalence (PP) at 4-weeks since the quit day. Secondary outcomes were self-
reported PP at 3 months, and continuous abstinence (CA) at 6 months.
Treatment evaluations were performed on the principle of intention-to-treat. Participants
who were lost to follow-up were treated as smokers. Generalized linear mixed models were
fit to estimate the overall treatment effect, while accounting for clustering within individual
studies. Estimates were adjusted for age, biological sex, socioeconomic status (SES), previous
quit attempts, and the baseline Fagerstrom score. Consistency of intervention effects with
participants’ sex and nicotine dependence at baseline were tested.
Results
The primary outcome at 4 weeks was evaluated in all five studies, while the secondary outcomes
on smoking status at 3 and 6 months were only available in some of the studies.The sample sizes
varied from 151 to 5,792 participants (Table 1).
Table 1: Summary of IndividualTrials
STOMP NZ
2001-03
(N=1705)
Text2Stop
UK 2008-09
(N=5792)
Text2Quit
USA 2012
(N=503)
SMS USA
2012 (N=164)
SMS Turkey
2012 (N=151)
Participants Aged 16 years or
older, smoking
cigarettes daily,
interested in
quitting within
the next month,
own a mobile
phone and able
to send/receive
text messages,
English speaking,
able to give
informed consent
Aged 16 years
or older, willing
to make an
attempt to quit
smoking in the
next month, own
a mobile phone,
able to give
informed consent
Aged 18 years or
order, smoking
five or more
cigarettes a
day, have a U.S
mailing address,
have an email
address, own
a cell phone
number with an
unlimited SMS
plan, interested
in quitting in the
next month, not
be pregnant
Aged 18-25
years, English
speaking, owning
a cell phone with
an unlimited SMS
plan, smoking
24 cigarettes or
more per week,
seriously thinking
about quitting
in the next 30
days, agreeing
to smoking
cessation status
verification by a
significant other
Aged 18 years or
older, daily smokers,
living in Ankara
(Turkey), owning
a mobile phone
and having sent or
received at least 1
text message in the
past year; seriously
thinking about
quitting in the next
15 days, not having
a chronic or serious
illness
Intervention Regular,
personalized
text messages
providing
smoking
cessation advice,
support and
distraction
Motivational
messages and
behaviour change
techniques, 5
text messages a
day for the first 5
weeks and then
3 a week for the
next 26 weeks
A facilitated
text messaging
program
(Text2Quit)
consists primarily
of automated,
bidirectional text
messages. Emails
and a web portal
was offered
as supportive
features
Two weeks
of pre-quit
messages, and
then four weeks
of messages
post-quit day;
assigned a
Quit Buddy,
had access to a
Text Crave on-
demand feature,
and a website
that included
an online
community
Two weeks of pre-
quit messages, and
then four weeks of
messages post-quit
day
Control Text messages
every two weeks,
thanking them
for being in the
study.Those who
completed follow
up would be
rewarded
Fortnightly,
simple, short
text messages
related to the
importance of
trial participation
A web link to
Smokefree.gov
or Clearing the
Air. Study-related
reminder texts
via SMS, in 2
weeks prior to
each follow up
survey
An attention
matched control
program aimed at
improving sleep
and fitness
A brochure that
provided evidence-
based quitting tips
Assessments 4 weeks,
3 months,
6 months
4 weeks,
6 months
4 weeks,
3 months,
6 months*
4 weeks,
3 months
4 weeks,
3 months
* Repeated point prevalence abstinence was measured.
There were no commonly measured variables related to SES across the individual trials in
different countries.The following definitions (Table 2), while not the same measures, were used
for the purpose of this meta-analysis.A Fagerstrom score (ranged 0-10) of 5 or more was
considered as a high level of nicotine dependence.
Table 2. Definitions of socioeconomic status (SES)
SES STOMP TEXT2STOP TEXT2QUIT SMS USA SMS TURKEY
Low < 15,000 NZDx ≤ 16 years Some high
school/college
< 15,000 USD <2,000YTL
High ≥ 15,000 NZD > 16 years College graduate
and above
≥ 15,000 USD ≥ 2,000YTL
No evidence of heterogeneity was observed across individual studies. Overall, 51% of the trial
participants were males; 45% were defined as low SES (see Table 2); 54% had high nicotine
dependence; 30% smoked their first cigarette within 5 minutes of waking up, 50% smoked 11-20
cigarettes each day.The participants were aged on average 34 years (SD 12; range 16-89), had on
average 4 previous quit attempts (SD 8) with a mean Fagerstrom score of 4.6 (SD 2.4).
At 4 weeks, 28.6% of the smokers in the intervention group (n=1200/4202) self-reported quitting
smoking, compared with 12.3% in the control group (n=507/4113).Age in years was the only
significant covariate in the model, indicating an increased chance of quitting with age.Table 3
presents the results in both adjusted odds ratio (OR) and relative risk (RR).
References
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support delivered via mobile phone text messaging (txt2stop): a single-blind, randomised trial’. Lancet, 378:49-55, 2011.
3. Abroms, L.C., Boal,A.L., Simmens, S.J., Mendel, J.A.,Windsor, R.A.‘A randomized trial of Text2Quit: a text messaging program for smoking
cessation’.Am J Prev Med (in press), 2014
4. Ybarra, M.L., Holtrop, J.S., Prescott,T.L., Rahbar, M.H., Strong, D.‘Pilot RCT results of Stop My Smoking USA: a text messaging-based smoking
cessation program for young adults’. Nicotine & Tobacco Research, 15(8):1388-1399, 2013.
5. Heatherton T.F., Kozlowski, L.T., Frecker, R.C., Fagerstrom, KO.,‘The Fagerstrom Test for Nicotine Dependence: a revision of the Fagerstrom
Tolerance Questionnaire’. British Journal of Addiction, 86:1119-1127, 1991.
Contact details
DrYannan Jiang, y.jiang@auckland.ac.nz
Senior Research Fellow / Biostatistician
The University of Auckland,Auckland, New Zealand
Department of Statistics