Received: 2 March 2023 Accepted: 17 April 2024
DOI: 10.1111/add.16528
RESEARCH REPORT
Effect of a peer-led prevention program (P2P) on smoking
in vocational high school students: Results from a
two-school-year cluster-randomized trial
Olivier Lareyre 1,2 | Florence Cousson-Gélie 1,2 | Bruno Pereira 3 |
Anne Stoebner-Delbarre 4 | Céline Lambert 3 | Mathieu Gourlan 1,2
1
Epidaure-Prevention Department of the Abstract
Montpellier Cancer Institute, Montpellier
Cancer Institute, Montpellier, France Aims: The aim of this work was to measure the impact of P2P (i.e. peer-to-peer), a peer-
2
Univ. Paul Valéry Montpellier 3, EPSYLON led smoking prevention intervention, on daily smoking prevalence of adolescents over
UR 4556, F34000, Montpellier, France
2 school years.
3
CHU Clermont-Ferrand, Biostatistics Unit,
DRCI, Clermont-Ferrand, France
Design: A cluster-randomized controlled trial was performed over a 16-month follow-up
4
Onco-Addiction and Patient Education Unit- (trial status: closed to follow-up). P2P was implemented 1–3 and 13–15 months after
Supportive Care Department, Montpellier baseline. Assessments took place at baseline and 4, 10 and 16 months after baseline.
Cancer Institute, Montpellier, France
The research team, assessors and adolescents were blinded to the study-arm assignment
Correspondence only at baseline.
Florence Cousson-Gélie, Epidaure-Prevention
Department of the Montpellier Cancer
Setting: Fifteen vocational high schools in France were randomized into two clusters,
Institute, Montpellier Cancer Institute, 208 using a 1:1 allocation ratio per French department (n intervention = 7, n control = 8).
Avenue des Apothicaires, 34298 Montpellier
cedex 5, France.
Participants: Participants comprised a sample of 2010 students in year 11 (i.e. 15–
Email: 16 years) in vocational high schools. A total of 437 students could not be assessed at
baseline (absent or left school), yielding a total sample of 1573 students
Funding information
SIRIC Montpellier Cancer, Grant/Award (n intervention = 749, n control = 824).
Number: INCa-DGOS-Inserm 6045; French
Intervention and comparator: The P2P programme trained voluntary students to
National Cancer Institute, Grant/Award
Number: INCa ‘Interventional research to become peer educators and design smoking prevention actions for their schoolmates in
reduce social inequalities’ 2013–033
the intervention group (n = 945 students), compared with a passive control group
(n = 1065 students).
Measurements: The primary outcome was change from baseline in the prevalence of
self-reported daily smoking (i.e. at least one cigarette per day) at 16 months.
Findings: The ‘time × group’ interaction indicated that, compared with the control group,
the intervention group had statistically significantly fewer daily smokers after 16 months
[odds ratio (OR) = 0.33, 95% confidence interval (CI) = 0.20, 0.53]. Similarly, compared
with the control group, the intervention group had statistically significantly fewer daily
smokers after 4 months (OR = 0.50, 95% CI = 0.30, 0.82) and 10 months (OR = 0.60,
95% CI = 0.37, 0.98). No adverse events of P2P2 were reported.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any
medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
© 2024 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.
1616 wileyonlinelibrary.com/journal/add Addiction. 2024;119:1616–1628.
, 13600443, 2024, 9, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/add.16528 by (UNICANCER) Institut régional du Cancer de Montpellier, Wiley Online Library on [26/08/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License
EFFECT OF A PEER-LED PREVENTION PROGRAMME 1617
Conclusions: A cluster-randomized trial found evidence that the peer-led P2P (peer-to-
peer) smoking prevention intervention reduced the uptake of daily smoking among high
school students in France over 16 months.
KEYWORDS
Disparities, high school, peer-to-peer, prevention, randomized controlled trial, tobacco
I N T R O D U CT I O N adolescents appear higher than in many other countries [29–31].
However, to date, no previous research has evaluated the efficacy of a
World-wide, tobacco use remains the most common cause of prevent- peer-led smoking prevention intervention among French adoles-
able deaths [1]. Most smokers initiate the habit as adolescents, with an cents [32]. Despite their high smoking acceptability and prevalence,
estimated 80% of adult smokers beginning before age 18 [2]. Smoking French adolescents might be sensitive to the credibility, shared cul-
uptake during adolescence is additionally associated with more ciga- tural background and empathy surrounding a peer-led approach [25,
rettes smoked in adulthood [3] and lower quit rates [4]. The increase in 33], which may thus limit their potentially defensive reactions to a
smoking prevalence during the adolescent years has long been reported smoking intervention [34]. Secondly, determining whether some indi-
in many countries world-wide [5–7]. For example, 10 years ago daily vidual characteristics may moderate the efficacy of peer-led interven-
smoking prevalence in France was estimated to be 8% at 13 years and tions is a research priority [28]. Identifying moderators means
31% at 18 years, with similar rates for boys and girls [8]. Encouragingly, determining whether the impact of peer-led interventions significantly
recent studies have reported a decline in the current smoking rates of differs in the function of subgroups of adolescents [35]. Such an
adolescents compared with previous reports [9–11]. However, despite approach enables useful recommendations to be made to practitioners
this positive trend, the smoking prevalence of adolescents remains high and policymakers, such as whether there are individuals for whom
in some countries [12], such as France (21% of daily smokers) [13] or peer-led interventions are most likely to work [35]. While gender or
Lithuania (21% of weekly smokers) [14]. In addition, some studies subjective measures of financial status have been identified as poten-
emphasize that there are important disparities between adolescents tially important moderators of health interventions [28, 36], less is
regarding smoking behaviour [15]. For instance, the smoking preva- known regarding this topic for peer-led interventions [28]. Only three
lence of adolescents in technical and vocational high schools, which are randomized controlled trials have examined gender differences and
educational establishments offering work-study programmes with com- reported no gender effect [37–39] (n = 1768, n = 998 and n = 9666,
panies, enabling students to acquire skills, knowledge and experience in respectively). Those results contrast with a meta-analysis reporting
a particular profession, is higher than among other adolescents in that school-based smoking prevention interventions, delivered mainly
numerous countries [16–18]. From those reports, tobacco prevention by teachers or health professionals, have a significantly higher impact
efforts targeting adolescents remain essential [2, 19, 20]. upon girls, at least for trials with a follow-up of 1 year or less [40]. As
The peer-led approach has been proposed as a potentially effec- the efficacy of many smoking prevention strategies is likely to vary in
tive way to address substance use in adolescents [21]. Indeed, function of gender [41, 42], it appears important to continue to
although other adolescents’ smoking behaviour may influence an ado- explore whether peer-led interventions can indeed be considered as
lescent’s tobacco consumption through peer pressure or peer selection one of the strategies relevant for both genders, notably in the French
[22, 23], it is acknowledged that the influence of other adolescents can context. Factors related to subjective measures of social or financial
also be protective through peer education [24]. Peers have great credi- status are also recognized as key aspects to take into account, over
bility, a shared cultural background and good understanding and empa- and above socio-economic status [36]. In a 5-year cohort study
thy surrounding the smoking behaviour of their counterparts, which (n = 3364), low perception of one’s overall personal financial situation
may reinforce the acceptability and efficacy of messages and actions was positively related to smoking behaviour in young people [43].
related to smoking prevention in adolescents [25–27]. However, the differential impact of this factor upon interventions tar-
A recent meta-analysis (10 randomized controlled trials, geting smoking behaviour remains largely explored [44], and even not
n = 13 706) reported that interventions relying upon a peer-led explored by previous peer-led interventions [28].
approach were effective in preventing smoking in adolescents [odds
ratio (OR) = 0.78, 95% confidence interval (CI) = 0.62, 0.99, follow-up
duration of studies = 6 months–3 years] [28]. Despite those promising Aims and hypotheses
results, some important issues regarding the efficacy and effectiveness
of peer-led interventions to impact upon smoking in adolescents still The primary purpose of this study was to evaluate the 16-month effect
have to be determined. First, most peer-led interventions have been (i.e. 2 school years) of P2P (peer-to-peer), a peer-led intervention aim-
implemented in Anglo-American countries (e.g. United States, ing to impact daily smoking prevalence of French high school students.
United Kingdom) [28]. France appears as an intriguing context, as P2P was implemented among students in vocational high schools, as
smoking acceptability and prevalence of smoking among French smoking prevalence in this population is higher than that of other
DOI: 10.1111/add.16528
RESEARCH REPORT
Effect of a peer-led prevention program (P2P) on smoking
in vocational high school students: Results from a
two-school-year cluster-randomized trial
Olivier Lareyre 1,2 | Florence Cousson-Gélie 1,2 | Bruno Pereira 3 |
Anne Stoebner-Delbarre 4 | Céline Lambert 3 | Mathieu Gourlan 1,2
1
Epidaure-Prevention Department of the Abstract
Montpellier Cancer Institute, Montpellier
Cancer Institute, Montpellier, France Aims: The aim of this work was to measure the impact of P2P (i.e. peer-to-peer), a peer-
2
Univ. Paul Valéry Montpellier 3, EPSYLON led smoking prevention intervention, on daily smoking prevalence of adolescents over
UR 4556, F34000, Montpellier, France
2 school years.
3
CHU Clermont-Ferrand, Biostatistics Unit,
DRCI, Clermont-Ferrand, France
Design: A cluster-randomized controlled trial was performed over a 16-month follow-up
4
Onco-Addiction and Patient Education Unit- (trial status: closed to follow-up). P2P was implemented 1–3 and 13–15 months after
Supportive Care Department, Montpellier baseline. Assessments took place at baseline and 4, 10 and 16 months after baseline.
Cancer Institute, Montpellier, France
The research team, assessors and adolescents were blinded to the study-arm assignment
Correspondence only at baseline.
Florence Cousson-Gélie, Epidaure-Prevention
Department of the Montpellier Cancer
Setting: Fifteen vocational high schools in France were randomized into two clusters,
Institute, Montpellier Cancer Institute, 208 using a 1:1 allocation ratio per French department (n intervention = 7, n control = 8).
Avenue des Apothicaires, 34298 Montpellier
cedex 5, France.
Participants: Participants comprised a sample of 2010 students in year 11 (i.e. 15–
Email: 16 years) in vocational high schools. A total of 437 students could not be assessed at
baseline (absent or left school), yielding a total sample of 1573 students
Funding information
SIRIC Montpellier Cancer, Grant/Award (n intervention = 749, n control = 824).
Number: INCa-DGOS-Inserm 6045; French
Intervention and comparator: The P2P programme trained voluntary students to
National Cancer Institute, Grant/Award
Number: INCa ‘Interventional research to become peer educators and design smoking prevention actions for their schoolmates in
reduce social inequalities’ 2013–033
the intervention group (n = 945 students), compared with a passive control group
(n = 1065 students).
Measurements: The primary outcome was change from baseline in the prevalence of
self-reported daily smoking (i.e. at least one cigarette per day) at 16 months.
Findings: The ‘time × group’ interaction indicated that, compared with the control group,
the intervention group had statistically significantly fewer daily smokers after 16 months
[odds ratio (OR) = 0.33, 95% confidence interval (CI) = 0.20, 0.53]. Similarly, compared
with the control group, the intervention group had statistically significantly fewer daily
smokers after 4 months (OR = 0.50, 95% CI = 0.30, 0.82) and 10 months (OR = 0.60,
95% CI = 0.37, 0.98). No adverse events of P2P2 were reported.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any
medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
© 2024 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.
1616 wileyonlinelibrary.com/journal/add Addiction. 2024;119:1616–1628.
, 13600443, 2024, 9, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/add.16528 by (UNICANCER) Institut régional du Cancer de Montpellier, Wiley Online Library on [26/08/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License
EFFECT OF A PEER-LED PREVENTION PROGRAMME 1617
Conclusions: A cluster-randomized trial found evidence that the peer-led P2P (peer-to-
peer) smoking prevention intervention reduced the uptake of daily smoking among high
school students in France over 16 months.
KEYWORDS
Disparities, high school, peer-to-peer, prevention, randomized controlled trial, tobacco
I N T R O D U CT I O N adolescents appear higher than in many other countries [29–31].
However, to date, no previous research has evaluated the efficacy of a
World-wide, tobacco use remains the most common cause of prevent- peer-led smoking prevention intervention among French adoles-
able deaths [1]. Most smokers initiate the habit as adolescents, with an cents [32]. Despite their high smoking acceptability and prevalence,
estimated 80% of adult smokers beginning before age 18 [2]. Smoking French adolescents might be sensitive to the credibility, shared cul-
uptake during adolescence is additionally associated with more ciga- tural background and empathy surrounding a peer-led approach [25,
rettes smoked in adulthood [3] and lower quit rates [4]. The increase in 33], which may thus limit their potentially defensive reactions to a
smoking prevalence during the adolescent years has long been reported smoking intervention [34]. Secondly, determining whether some indi-
in many countries world-wide [5–7]. For example, 10 years ago daily vidual characteristics may moderate the efficacy of peer-led interven-
smoking prevalence in France was estimated to be 8% at 13 years and tions is a research priority [28]. Identifying moderators means
31% at 18 years, with similar rates for boys and girls [8]. Encouragingly, determining whether the impact of peer-led interventions significantly
recent studies have reported a decline in the current smoking rates of differs in the function of subgroups of adolescents [35]. Such an
adolescents compared with previous reports [9–11]. However, despite approach enables useful recommendations to be made to practitioners
this positive trend, the smoking prevalence of adolescents remains high and policymakers, such as whether there are individuals for whom
in some countries [12], such as France (21% of daily smokers) [13] or peer-led interventions are most likely to work [35]. While gender or
Lithuania (21% of weekly smokers) [14]. In addition, some studies subjective measures of financial status have been identified as poten-
emphasize that there are important disparities between adolescents tially important moderators of health interventions [28, 36], less is
regarding smoking behaviour [15]. For instance, the smoking preva- known regarding this topic for peer-led interventions [28]. Only three
lence of adolescents in technical and vocational high schools, which are randomized controlled trials have examined gender differences and
educational establishments offering work-study programmes with com- reported no gender effect [37–39] (n = 1768, n = 998 and n = 9666,
panies, enabling students to acquire skills, knowledge and experience in respectively). Those results contrast with a meta-analysis reporting
a particular profession, is higher than among other adolescents in that school-based smoking prevention interventions, delivered mainly
numerous countries [16–18]. From those reports, tobacco prevention by teachers or health professionals, have a significantly higher impact
efforts targeting adolescents remain essential [2, 19, 20]. upon girls, at least for trials with a follow-up of 1 year or less [40]. As
The peer-led approach has been proposed as a potentially effec- the efficacy of many smoking prevention strategies is likely to vary in
tive way to address substance use in adolescents [21]. Indeed, function of gender [41, 42], it appears important to continue to
although other adolescents’ smoking behaviour may influence an ado- explore whether peer-led interventions can indeed be considered as
lescent’s tobacco consumption through peer pressure or peer selection one of the strategies relevant for both genders, notably in the French
[22, 23], it is acknowledged that the influence of other adolescents can context. Factors related to subjective measures of social or financial
also be protective through peer education [24]. Peers have great credi- status are also recognized as key aspects to take into account, over
bility, a shared cultural background and good understanding and empa- and above socio-economic status [36]. In a 5-year cohort study
thy surrounding the smoking behaviour of their counterparts, which (n = 3364), low perception of one’s overall personal financial situation
may reinforce the acceptability and efficacy of messages and actions was positively related to smoking behaviour in young people [43].
related to smoking prevention in adolescents [25–27]. However, the differential impact of this factor upon interventions tar-
A recent meta-analysis (10 randomized controlled trials, geting smoking behaviour remains largely explored [44], and even not
n = 13 706) reported that interventions relying upon a peer-led explored by previous peer-led interventions [28].
approach were effective in preventing smoking in adolescents [odds
ratio (OR) = 0.78, 95% confidence interval (CI) = 0.62, 0.99, follow-up
duration of studies = 6 months–3 years] [28]. Despite those promising Aims and hypotheses
results, some important issues regarding the efficacy and effectiveness
of peer-led interventions to impact upon smoking in adolescents still The primary purpose of this study was to evaluate the 16-month effect
have to be determined. First, most peer-led interventions have been (i.e. 2 school years) of P2P (peer-to-peer), a peer-led intervention aim-
implemented in Anglo-American countries (e.g. United States, ing to impact daily smoking prevalence of French high school students.
United Kingdom) [28]. France appears as an intriguing context, as P2P was implemented among students in vocational high schools, as
smoking acceptability and prevalence of smoking among French smoking prevalence in this population is higher than that of other
