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Peer-facilitated community-based interventions for adolescent health in low- and middle-income countries: A systematic review

  • Kelly Rose-Clarke ,

    Roles Conceptualization, Data curation, Formal analysis, Writing – original draft, Writing – review & editing

    kelly.rose-clarke@kcl.ac.uk

    Affiliation Department of Global Health and Social Medicine, King’s College London, London, United Kingdom

  • Abigail Bentley,

    Roles Data curation, Writing – review & editing

    Affiliation Institute for Global Health, University College London, London, United Kingdom

  • Cicely Marston,

    Roles Conceptualization, Writing – review & editing

    Affiliation Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom

  • Audrey Prost

    Roles Conceptualization, Data curation, Formal analysis, Funding acquisition, Writing – review & editing

    Affiliation Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom

Abstract

Background

Adolescents aged 10–19 represent one sixth of the world’s population and have a high burden of morbidity, particularly in low-resource settings. We know little about the potential of community-based peer facilitators to improve adolescent health in such contexts.

Methods

We did a systematic review of peer-facilitated community-based interventions for adolescent health in low- and middle-income countries (LMICs). We searched databases for randomised controlled trials of interventions featuring peer education, counselling, activism, and/or outreach facilitated by young people aged 10–24. We included trials with outcomes across key areas of adolescent health: infectious and vaccine preventable diseases, undernutrition, HIV/AIDS, sexual and reproductive health, unintentional injuries, violence, physical disorders, mental disorders and substance use. We summarised evidence from these trials narratively. PROSPERO registration: CRD42016039190.

Results

We found 20 studies (61,014 adolescents). Fourteen studies tested interventions linked to schools or colleges, and 12 had non-peer-facilitated components, e.g. health worker training. Four studies had HIV-related outcomes, but none reported reductions in HIV prevalence or incidence. Nine studies had clinical sexual and reproductive health outcomes, but only one reported a positive effect: a reduction in Herpes Simplex Virus-2 incidence. Three studies had violence-related outcomes, two of which reported reductions in physical violence by school staff and perpetration of physical violence by adolescents. Seven studies had mental health outcomes, four of which reported reductions in depressive symptoms. Finally, we found eight studies on substance use, four of which reported reductions in alcohol consumption and smoking or tobacco use. There were no studies on infectious and vaccine preventable diseases, undernutrition, or injuries.

Conclusions

There are few trials on the effects of peer-facilitated community-based interventions for adolescent health in LMICs. Existing trials have mixed results, with the most promising evidence supporting work with peer facilitators to improve adolescent mental health and reduce substance use and violence.

Introduction

Adolescents (persons aged 10–19 years) constitute one sixth of the world’s population [1, 2]. Every year, 1.2 million die from preventable causes including road injury, self-harm, drowning, and interpersonal violence [3]. The burden of communicable diseases (HIV/AIDS, TB and malaria) is disproportionately high in this age group, and many non-communicable diseases in adulthood can be attributed to risk behaviours adopted during adolescence [2, 4, 5].

Global systematic reviews have found moderate- to high-quality evidence that interventions in communities and schools have positive effects on adolescent sexual and reproductive health, mental health, substance use, and intimate partner violence [610]. In several Low- and Middle-Income Countries (LMICs), peer facilitators, defined as adolescents or young adults selected from the group or community they serve, are employed to work in communities and schools as part of national and non-governmental adolescent health programmes. [1114]. There are several reasons for this. Training lay peer facilitators to deliver adolescent health interventions can increase capacity for scaling up and be more cost-effective than working with specialised staff [1517]. Peer facilitators may also be better able to communicate with adolescents than older adults, and perceived as a more credible source of information [18, 19]. Peer facilitators might have better access to marginalised groups who have limited engagement with existing health programmes [15, 20]. Critically, empowering young people to inform and implement adolescent health programmes should make these more relevant and effective [2]. The selection, training, supervision and incentivisation of peer facilitators are all deemed critical to success and sustainability [21].

Primary studies and reviews on the effects of peer-facilitated community interventions for adolescent health in LMICs have largely focused on sexual and reproductive health [15, 2225]. No existing systematic review has examined evidence for the effects of peer-facilitated interventions across multiple areas of adolescent health in LMICs, despite the fact that community interventions are likely to rely on the same human resources for many areas of adolescent health. To address this gap, we conducted a systematic review of community-based peer-facilitated interventions in LMICs for the key areas of adolescent health defined by the Lancet Commission on Adolescent Health and Wellbeing: infectious and vaccine preventable diseases, undernutrition, HIV and AIDS, sexual and reproductive health, unintentional injuries, violence, physical disorders, mental disorders and substance use [2].

Methods

We conducted the systematic review in accordance with the 2009 PRISMA statement (S1 Checklist) [26].

Inclusion criteria for the systematic review

We only included randomised controlled trials (RCTs) because these studies have a lower risk of bias compared to quasi-experimental studies. We included trials in which the majority (>50%) of participants were adolescents or participants with a mean or median age of 10–19. Trials had to be located in the community (e.g. schools, youth clubs or primary health care centres) because this is where peer-facilitated interventions are commonly located. Trials also had to take place in LMICs (as defined by the World Bank [27]), and test an intervention delivered in whole or part by peer facilitators, defined here as persons or a majority of persons (>50%) with a mean or median age of 10–24 recruited from the group or community meant to benefit from interventions. We included trials of interventions involving peer education where peers sought to increase adolescents’ knowledge or influence their attitudes, ‘counselling’, defined as peers providing support to help adolescents resolve personal or psychological problems, ‘activism’ involving peer-led campaigns to change health-related policy, and ‘outreach’ with peers engaging marginalised adolescents [28, 29]. We included trials with primary or secondary outcomes relevant to areas of health need outlined in the report of the Lancet Commission on Adolescent Health and Wellbeing [2]: infectious and vaccine preventable diseases, undernutrition, HIV and AIDS, sexual and reproductive health, unintentional injuries, violence, physical disorders, mental disorders and substance use. We deliberately included interventions from across multiple adolescent health areas in order to compare effects across areas. For each area of health need, we included studies with outcomes related to the diseases and risk factors highlighted by the Lancet Commission Report, as well as diseases constituting the 10 main global causes of death or years lived with disability for 10–19 year olds [2, 4]. These outcomes are shown in Table 1. We also included educational and employment marginalisation, which were considered key determinants of adolescent health. We did not include studies that were conducted in underprivileged populations in high-income countries. No date or language restrictions were applied. The review protocol is registered with PROSPERO (CRD42016039190). Our methods did not deviate from those specified in the protocol.

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Table 1. Outcomes included in the review by area of health need.

https://doi.org/10.1371/journal.pone.0210468.t001

Search strategy

KR-C used customised search strategies (S1 Text) to search for studies that met the inclusion criteria in Medline, Embase, Cochrane Library, CINAHL, African Index Medicus, Web of Science, Psycinfo and ERIC up to 9th March 2017. The search was later updated to 22nd June 2018. We identified ongoing studies by contacting adolescent health experts and searching the International Clinical Trials Registry Platform. We found further studies by searching relevant reviews. Fig 1 summarises the study selection process. KR-C or AB screened the title and abstract of each article to identify and exclude those that were irrelevant. KR-C and AB or AP then independently screened the full text of all remaining articles for relevance. Any discrepancies were discussed and resolved by the review team and/or by contacting authors. S2 Text outlines reasons for excluding articles at full text screening. S1 Table describes details of ongoing studies. We used Covidence and EndNote reference manager software to manage articles retrieved by the search [30].

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Fig 1. PRISMA 2009 Flow Diagram.

From: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLoS Med 6(7): e1000097. doi: 10.1371/journal.pmed1000097 For more information, visit www.prisma-statement.org.

https://doi.org/10.1371/journal.pone.0210468.g001

For each study that met the inclusion criteria, KR-C and AB or AP independently extracted data on general study details, trial design, participant characteristics, sample size, intervention, control condition, outcomes and summary measures, for example a risk ratio (RR), odds ratio (OR), or linear regression coefficient (β). We noted whether interventions involved education, counselling, activism and/or outreach strategies. We extracted data from the first outcome assessment post-intervention based on a hierarchy of clinical outcomes first (e.g. HSV-2 serum test), then outcomes related to self-reported symptoms (e.g. STD symptoms), and finally behavioural outcomes (e.g. condom use). We did not exclude studies on the basis of methodological quality, but used the Cochrane Collaboration’s Risk of Bias Tool to assess studies across the following bias domains: sequence generation, allocation concealment, participants and personnel blinding, outcome assessment blinding, incomplete outcome data, selective outcome reporting and other bias [31].

Data synthesis

We mapped the evidence using a narrative summary of intervention characteristics by area of health need. Within each area of health need, we also considered how complementary intervention activities, setting, type of facilitator and participant age could influence intervention effects. Although we initially planned to do a statistical meta-analysis, this was not possible because of the wide variation in types of interventions and outcomes.

Results

We found 43 articles that described 20 relevant randomised controlled trials with a total of 61,014 participants at baseline. S2 Table summarises the characteristics of these studies. Six were conducted in low-income countries, seven in lower-middle income countries and seven in upper middle-income countries. Fourteen interventions were linked to schools or a college. Twelve interventions had additional non-peer-facilitated components, for example health worker or teacher training, and dissemination of educational materials. These other non-peer-facilitated components are described in Table 2.

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Table 2. Characteristics of peer-facilitated components of adolescent health interventions and intervention effects.

https://doi.org/10.1371/journal.pone.0210468.t002

Peer-facilitated strategies

Table 2 describes the characteristics of peer-facilitated intervention strategies, including the selection, training and supervision of peers. Interventions were diverse: peer facilitators conducted education, counselling, outreach and activism.

Nineteen of the 20 studies featured peer education activities. Peers ran group-based sessions for classmates and other students [3236], facilitated groups in the community, [3741] performed street plays or created dramas [37, 4244], ran workshops with parents [45], and distributed educational materials [45, 46]. Nine of the 20 studies incorporated peer counselling strategies. These ranged from low intensity approaches where peers encouraged their classmates not to give or accept cigarettes [34], to higher intensity approaches where peers led manualised interpersonal psychotherapy groups [41]. Peer activism was used in five studies to develop and enforce anti-smoking/tobacco policies [34, 43], work with community leaders to provide opportunities for adolescents [45] and run a ‘student court’ to manage school discipline issues [42]. Peer outreach was used in four of the 19 studies. For example, in Thailand, peers used communication skills to convey risk reduction messages to drug users in their social networks [20]. As part of the CERCA (Community-Embedded Reproductive Health Care for Adolescents) intervention in Nicaragua, peers mentored adolescents to help them build decision-making competence related to sexual and reproductive health, and referred and accompanied them to health services when needed [45].

The duration of peer-facilitated components ranged from three weeks [47] to four years [39]. Training duration and intensity ranged from a one hour information session [35] to a four-week programme [46]. Peer facilitators were school students in nine of the 20 studies, and school graduates in six. Five studies did not provide information on the education level of facilitators.

Study quality was variable (Table 3): three studies were at low risk of bias across all seven domains [32, 40, 42]; 15 did not report methods used for allocation concealment; eight did not report methods for random sequence generation. One study was at high risk of bias because it had a small number of clusters and results were not adjusted for clustering or confounders [37]. In another, schools refused to participate after the baseline survey and it was not clear whether data were missing because of this or for other reasons [48]. Two studies encountered unexpectedly high rates of adolescent out-migration and were forced to change their study design substantially with implications for the statistical power of the study [39, 45]. In one study in Nicaragua, loss to follow up was 76%, with important differences between resurveyed adolescents and those lost to follow up [45].

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Table 3. Risk of bias assessments of studies of peer-facilitated interventions for adolescent health.

https://doi.org/10.1371/journal.pone.0210468.t003

Study outcomes and intervention effects

We did not identify any studies focusing on infectious and vaccine preventable diseases, undernutrition or unintentional injuries. More studies measured outcomes related to sexual and reproductive health (nine studies), substance use (eight studies) and mental disorders (seven studies) than any other area of health need. Below, and in Table 2, we present intervention details and findings by area of health need.

HIV and AIDS.

Four studies reported HIV/AIDS-related outcomes [20, 39, 40, 44]. All involved a community component and peer education. Two examined the effects of combining peer facilitation with programmes for parents, community stakeholders and health worker training [39, 44]. None of the four studies reported a positive effect of the interventions.

Sexual and reproductive health.

Only one study [40] found an effect of peer-facilitated interventions on clinical sexual and reproductive health outcomes: Jewkes et al tested the effects of a structured curriculum of peer-facilitated group education on sex and love, contraception and sexually transmitted diseases among adolescent boys and girls in South Africa, and reported a reduction in Herpes Simplex Virus-2 infection (HSV-2) (RR 0.67 CI 0.47–0.97) [40]. However, other studies found negative results: one study from Tanzania reported an increased prevalence of gonorrhoea among young women (RR 1.93 CI 1.01–3.71) following school-based reproductive health education led by teachers followed by scripted dramas by peer educators [44]. Another study from Thailand used a curriculum of group education and role-play sessions to help young men and women reduce their use of metamphetamines and sexual risk-taking, and to communicate with others in their social networks about these risks [20]. The study found an increased incidence rate of gonorrhoea in the intervention group compared to the control group (4.69 per 100 person years vs. 0.43 per 100 person years, p<0.05).

Self-reported symptoms of sexually transmitted diseases (STDs) were reduced in two studies from India and Nigeria [37, 46]. In Balaji et al.’s Indian study, complaints of vaginal symptoms and penile discharge only decreased significantly in urban areas (OR: 0.49, 95% CI: 0.26–0.93 and OR: 0.36, 95% CI: 0.24–0.55, respectively), where peer facilitators were linked to schools [37]. Peers were also trained and supported within schools in the study by Okonofua et al, which reported a reduction in self-reported symptoms of STIs in Nigeria (OR 0.63 CI 0.43–0.91) [46]. A trial of peer-led after-school life skills training sessions reported an increase in condom use among boys (β 0.217 p = 0.004) in Tanzania. A South African trial of peer-led interpersonal psychotherapy groups to help adolescents learn how to resolve distress and access emotional support also led to girls reporting more condom use among their partners (β 0.21 p = 0.02 [36, 41]. Conversely, one trial of peer mentors helping adolescents build competence in making deliberate choices and referring them to health facilities reported reduced condom use (β -2.66 p = 0.039) [45].

Violence.

Three studies reported violence-related outcomes, two of which found reductions in violence. Both of these successful interventions involved activities for teachers and adolescents and both used a combination of peer education, counseling and activism strategies. Devries et al evaluated the Good School Toolkit in Ugandan primary schools: students took part in intervention-implementing committees to reduce violence, create dramas and facilitate a student court to handle school discipline issues. They found reductions in past week and past term physical violence perpetrated by school staff, reported by students (past week: OR 0.39 CI 0.25–0.62; past term: OR 0.31 CI 0.18–0.53) [42]. They also reported a reduction in violence from peers, and a reduction in violence by school staff against adolescents who had functional difficulties and/or a disability [49]. Balaji et al.’s Yuva Mitr (Friend of Youth) intervention reduced perpetration of physical violence (rural areas OR 0.29 CI 0.15–0.57; urban areas OR 0.59 CI 0.40–0.87) and the experience of sexual violence (urban areas only: OR 0.19 CI 0.09–0.41) among adolescents in India [37]. Whilst the study by Devries et al. focused on reducing violence, Yuva Mitr sought to affect multiple areas of adolescent health through a multi-component intervention involving peer education, community activities, teacher training and dissemination of health materials.

Physical disorders.

Only two studies reported outcomes relating to physical disorders. A school-based peer education intervention in Jordan improved quality of life among adolescents with asthma (mean difference 1.35 CI 1.04–1.76) [32]. An evaluation of a multicomponent school-based intervention to improve adolescent health and nutrition in India–judged to be at high risk of bias—measured no effect on BMI [50].

Mental disorders.

Interventions for mental disorders were diverse and included peer outreach, counselling and education interventions that addressed determinants of mental health such as violence and substance use. Four of the seven studies with mental health outcomes reported improvements in depressive symptoms [19,36,46,50]. These four interventions were from diverse locations (Uganda, Philippines, India and Thailand) and involved a range of peer-facilitated strategies (education, outreach and counselling). Only one [47] of the four positive studies focused on an actual mental disorder, and reported a reduction in the severity of depression. Three of these four successful interventions were linked to schools or colleges [37, 47, 51].

Substance use.

Four out of eight studies reporting substance use outcomes found positive effects. Interventions reduced alcohol drinking among young men (OR 0.68 CI 0.49–0.94) [40] and the risk of non-smokers becoming regular smokers (OR 2.23 CI 1.20–3.85) [35]. One study in urban schools in India tested Project MYTRI, a multi-component intervention with classroom curricula, a poster campaign and peer-led activism. The study found between-group differences in the rate of growth of cigarette smoking (p = 0.05), bidi smoking (p<0.01), and any tobacco use (p = 0.04) among students [48]. Among urban adolescents in India, Balaji et al reported a reduction in use of tobacco, cigarettes and alcohol (OR 0.63 CI 0.45–0.89) [37]. Three [35, 37, 48] of the four studies reporting positive effects were linked to schools, including two where school students acted as peer facilitators [35, 48].

Educational and employment marginalisation.

Only two studies measured effects on educational and employment marginalisation [38, 51]. In Tanzania, the Young Citizens Programme aimed to develop adolescents’ individual and collective efficacy to raise awareness of HIV [38]. One outcome in this trial was academic self-efficacy (e.g. “I have learned how hard work helps me in math”), but there were no improvements in this outcome. The Suubi intervention in Uganda was aimed at AIDS-orphaned adolescents and involved a microfinance intervention, financial education and mentorship by older peers aged 17–23. Evaluation of the programme showed an increase in the number of adolescents saying they planned to go to secondary school and that they were more certain they could accomplish their education goals [51].

Discussion

Our systematic review is the first to summarise results from trials of peer-facilitated interventions for all areas of adolescent health in LMICs: to our knowledge, the only other review of peer-facilitated interventions to assess effects for multiple health outcomes was conducted in 1999 and mainly included studies from high-income countries [28]. We found 20 trials focused on six of the nine areas identified by the Lancet Commission for Adolescent Health and Wellbeing: sexual and reproductive health, HIV/AIDS, physical disorders, mental health, violence, and substance use. There was some evidence that interventions improved mental health and reduced violence and substance use, but the diversity of components and outcomes prevented us from making definitive statements about effectiveness. We found no trials with positive effects on HIV-related outcomes, heterogenous results for physical disorders and sexual and reproductive health outcomes, and no trials on infectious and vaccine preventable diseases, undernutrition, or injuries.

Our review has three main limitations. The diversity of interventions and outcomes prevented us from meta-analysing the data within or across adolescent health areas. It also prevented us from understanding the extent to which facilitator characteristics, other intervention components and locations (e.g. school vs. non-school components) might explain heterogenous results within areas. To remedy this, future studies could provide more accurate descriptions of the content of interventions, and use comparable outcome measures within areas of adolescent health need. Further reviews could also focus on individual adolescent health areas and examine a broader range of study designs and methods.

A second limitation was our inability to assess publication bias. Although we contacted authors for clarifications, many articles screened lacked information about facilitator age, and we may not have identified all eligible studies [43, 45]. Risk of bias was variable across studies, with no specific pattern within and across areas.

Finally, several trials only included our outcomes of interest as secondary indicators. For example, some were powered to detect differences in sexual and reproductive health outcomes but also included outcomes related to violence and mental health [39]. Such trials may have been under-powered to detect significant differences between intervention and control arms for secondary indicators, and prone to false positive (Type I errors) due to multiple testing.

In line with previous systematic reviews, we found heterogeneous effects of peer-facilitated interventions on sexual and reproductive health, suggesting that peer facilitation alone is unlikely to be the solution to improving this area of health [15, 52, 53]. This is unsurprising given the breadth and strength of socio-political factors affecting sexuality and access to services for sexual and reproductive health.

We found more promising evidence for peer-facilitated interventions to improve adolescents’ mental health and reduce violence and substance use, but too much heterogeneity in interventions and outcomes to make definitive conclusions. Effects on mental health, violence and substance use have some plausibility: peer-facilitated interventions can strengthen peer networks, increase social support, change social norms and improve school environments [10, 54].

Fourteen out of 20 studies in our review examined interventions with a school- or college-based component, including three out of four studies with positive effects on depressive symptoms, and all positive studies on violence. There are many potential benefits to locating interventions in schools: there may be pre-existing support systems for peer facilitators, and facilitators have a ‘captive audience’ of participants in a classroom setting [55]. Potential disadvantages of working in schools include the potential for hierarchies between teachers, peer facilitators and participants to hinder communication, a lack of engagement with out-of-school adolescents, and the risk of entire schools dropping out of the intervention [28]. Previous studies have shown that using peer facilitators rather than teachers to deliver health education does not necessarily make an intervention more effective [28]. This may be because peer facilitation often involves implementing interventions developed by older adults. The benefits of such interventions could be lost if adolescents feel the intervention is no longer relevant or that they cannot relate to peer facilitators. Successful school-based interventions in this review were largely devised by research teams, though half consulted with young people during intervention design or implementation phases [37, 42, 46, 48]. More formalised involvement of adolescents in the development of peer-facilitated interventions is likely to be beneficial [24, 28, 52].

We identified two peer-facilitated interventions that engaged adolescents in peer leadership roles, and focused on capacity building rather than knowledge transfer [20, 38, 56]. These interventions had positive outcomes for mental health and self-efficacy (deliberative and communicative self-efficacy and emotional control). Interventions that engage a higher proportion of peer leaders may be more sustainable in populations with high rates of adolescent mobility, where retaining peer facilitators may be challenging. Interventions that engage peer facilitators in mobilising communities of young people have been successful in non-school settings [20, 38]. Reaching young people who are not in school is important to ensure equity. Offering them leadership opportunities through participatory interventions might help to achieve this.

Critically, twelve of the studies in this review involved interventions with additional, non-peer-facilitated components, with evidence of positive effects on mental disorders, violence and substance use. The enthusiasm for multi-component interventions—while challenging from the point of view of attribution—reflects the widespread acceptance that adolescent vulnerabilities are influenced by factors at multiple, interacting socio-ecological levels. Reviews of interventions for the prevention of violence have highlighted that interventions with multiple components that address these multiple layers are more likely to succeed than interventions that only address one [28]. These multi-component interventions require evaluations that theorise and assess the interaction between peer and non-peer-facilitated components, or the environment within which interventions are delivered as complex system [57, 58].

In conclusion, peer-facilitated community-based interventions show promise to improve mental health and reduce violence and substance use in LMICs, though further robust studies are needed to strengthen the evidence base. Future research should focus on theorising and assessing the contribution of peer-facilitated interventions and their interactions with non-peer-facilitated components in these areas of adolescent health.

Supporting information

S1 Text. Sample search strategy for Medline.

https://doi.org/10.1371/journal.pone.0210468.s001

(DOCX)

S1 Table. Articles of potentially eligible registered studies or study protocols for which we did not find published results.

https://doi.org/10.1371/journal.pone.0210468.s003

(DOCX)

S2 Table. Characteristics of studies of community-based peer-facilitated interventions for adolescent health.

https://doi.org/10.1371/journal.pone.0210468.s004

(DOCX)

Acknowledgments

This study was funded by the Children’s Investment Fund Foundation. We thank Hassan Haghparast-Bidgoli and Ni Yanyan for their help translating non-English articles, and Heather Chesters for her advice on search strategies for the electronic database search.

References

  1. 1. UNICEF. Progress for children: a report card for adolescents. 2012 April 2012. Report No.: Contract No.: 10.
  2. 2. Patton GC, Sawyer SM, Santelli JS, Ross DA, Afifi R, Allen NB, et al. Our future: a Lancet commission on adolescent health and wellbeing. Lancet. 2016;387(10036):2423–78. pmid:27174304
  3. 3. World Health Organization. Global health estimates 2015: deaths by cause, age, sex, by country and by region, 2000–2015 Geneva2016. http://www.who.int/healthinfo/global_burden_disease/estimates/en/index1.html.
  4. 4. Mokdad AH, Forouzanfar MH, Daoud F, Mokdad AA, El Bcheraoui C, Moradi-Lakeh M, et al. Global burden of diseases, injuries, and risk factors for young people’s health during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2016;387(10036):2383–401. pmid:27174305
  5. 5. Viner RM, Coffey C, Mathers C, Bloem P, Costello A, Santelli J, et al. 50-year mortality trends in children and young people: a study of 50 low-income, middle-income, and high-income countries. Lancet. 2011;377(9772):1162–74. pmid:21450338
  6. 6. Shackleton N, Jamal F, Viner RM, Dickson K, Patton G, Bonell C. School-based interventions going beyond health education to promote adolescent health: systematic review of reviews. Journal of Adolescent Health. 2016;58(4):382–96. pmid:27013271
  7. 7. Salam RA, Faqqah A, Sajjad N, Lassi ZS, Das JK, Kaufman M, et al. Improving adolescent sexual and reproductive health: a systematic review of potential interventions. Journal of Adolescent Health. 2016;59(4):S11–S28.
  8. 8. Das JK, Salam RA, Arshad A, Finkelstein Y, Bhutta ZA. Interventions for adolescent substance abuse: an overview of systematic reviews. Journal of Adolescent Health. 2016;59(4):S61–S75.
  9. 9. Das JK, Salam RA, Lassi ZS, Khan MN, Mahmood W, Patel V, et al. Interventions for adolescent mental health: an overview of systematic reviews. Journal of Adolescent Health. 2016;59(4):S49–S60.
  10. 10. De Koker P, Mathews C, Zuch M, Bastien S, Mason-Jones AJ. A systematic review of interventions for preventing adolescent intimate partner violence. Journal of Adolescent Health. 2014;54(1):3–13. pmid:24125727
  11. 11. Government of India. Rashtriya Kishor Swasthya Karyakram operational framework: translating strategy into programmes. 2014.
  12. 12. Uganda Ministry of Health. The National Adolescent Health Strategy: 2011–2015. 2011.
  13. 13. Federal Democratic Republic of Ethiopia Ministry of Health. National adolescent and youth reproductive health strategy: 2007–2015. 2007.
  14. 14. Nepal Ministry of Health. National adolescent health and development strategy. 2000.
  15. 15. Medley A, Kennedy C, O’Reilly K, Sweat M. Effectiveness of peer education interventions for HIV prevention in developing countries: a systematic review and meta-analysis. AIDS Education and Prevention. 2009;21(3):181–206. pmid:19519235
  16. 16. Visser MJ. HIV/AIDS prevention through peer education and support in secondary schools in South Africa. SAHARA-J. 2007;4(3):678–94. pmid:18185895
  17. 17. Townsend JW, Diaz de May E, Sepúlveda Y, Santos de Garza Y, Rosenhouse S. Sex education and family planning services for young adults: alternative urban strategies in Mexico. Studies in Family Planning. 1987;18(2):103–8. pmid:3590264
  18. 18. Australian Injecting & Illicit Drug Users League (AIVL). A framework for peer education by drug-user organisations. 2006.
  19. 19. Turner G, Shepherd J. A method in search of a theory: peer education and health promotion. Health Education Research. 1999;14(2):235–47. pmid:10387503
  20. 20. Sherman SG, Sutcliffe C, Srirojn B, Latkin CA, Aramratanna A, Celentano DD. Evaluation of a peer network intervention trial among young methamphetamine users in Chiang Mai, Thailand. Social Science & Medicine. 2009;68(1):69–79. pmid:18986746
  21. 21. UNAIDS. Peer education and HIV/AIDS: concepts, uses and challenges. Geneva, Switzerland: 1999.
  22. 22. Askew I, Chege J, Njue C, Radeny S. A multi-sectoral approach to providing reproductive health information and services to young people in Western Kenya: Kenya adolescent reproductive health project. New York: Population Council, 2004.
  23. 23. Brieger WR, Delano GE, Lane CG, Oladepo O, Oyediran KA. West African Youth Initiative: Outcome of a reproductive health education program. Journal of Adolescent Health. 2001;29:436–46. pmid:11728893
  24. 24. Maticka-Tyndale E, Penwell Barnett J. Peer-led interventions to reduce HIV risk of youth: a review. Evaluation and program planning. 2009;33:98–112. pmid:19647874
  25. 25. Plan UK. Reaching out: a learning guide for health programming with adolescents. 2014.
  26. 26. Moher D, Liberati A, Tetzlaff J, Altman DG. The PRISMA Group (2009) Preferred reporting items for systematic review and meta-analyses: the PRISMA statement. PLoS Medicine. 2009;6:e1000097. pmid:19621072
  27. 27. World Bank. World Development Indicators [cited 2016 June].
  28. 28. Harden A, Weston R, Oakley A. A review of the effectiveness and appropriateness of peer-delivered health promotion interventions for young people. London: Institute of Education, University of London, 1999.
  29. 29. World Health Organization. Health topics: Health education 2016 [cited 2016 24 August]. http://www.who.int/topics/health_education/en/.
  30. 30. Veritas Health Innovation. Covidence systematic review software Melbourne, Australia. http://www.covidence.org.
  31. 31. Higgins JPT, Altman DG, Gøtzsche PC, Jüni P, Moher D, Oxman AD, et al. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. British Medical Journal. 2011;343:d5828.
  32. 32. Al-sheyab N, Gallagher R, Crisp J, Shah S. Peer-led education for adolescents with asthma in Jordan: a cluster-randomized controlled trial. Pediatrics. 2012;129(1):e106–12. pmid:22157137
  33. 33. Ayaz S, Açıl D. Comparison of peer education and the classic training method for school aged children regarding smoking and its dangers. Journal of Pediatric Nursing. 2014;30:e3–e12.
  34. 34. Chen L, Chen Y, Hao Y, Gu J, Guo Y, Ling W. Effectiveness of school-based smoking intervention in middle school students in Linzhi Tibetan and Guangzhou Han ethnicity in China. Addictive Behaviors. 2014;39(189–195). pmid:24129264
  35. 35. Lotrean LM, Dijk F, Mesters I, Ionut C, De Vries H. Evaluation of a peer-led smoking prevention programme for Romanian adolescents. Health Education Research. 2010;25(5):803–14. pmid:20601383.
  36. 36. Mmbaga EJ, Kajula L, Aaro LE, Kilonzo M, Wubs AG, Eggers SM, et al. Effect of the PREPARE intervention on sexual initiation and condom use among adolescents aged 12–14: a cluster randomised controlled trial in Dar es Salaam, Tanzania. Bmc Public Health. 2017;17. pmid:28415973
  37. 37. Balaji M, Andrews T, Andrew G, Patel V. The acceptability, feasibility and effectiveness of a population-based intervention to promote youth health: an exploratory study in Goa, India. Journal of Adolescent Health. 2011;48:453–60. pmid:21501803
  38. 38. Carlson M, Brennan RT, Earls F. Enhancing adolescent self-efficacy and collective effiacy through public engagement around HIV/AIDS competence: a multilevel, cluster randomised-controlled trial. Social Science & Medicine. 2012;75:1078–87.
  39. 39. Cowan FM, Pascoe SJ, Langhaug LF, Mavhu W, Chidiya S, Jaffar S, et al. The Regai Dzive Shiri project: results of a randomized trial of an HIV prevention intervention for youth. AIDS (London, England) [Internet]. 2010; 24(16):[2541–52 pp.]. http://onlinelibrary.wiley.com/o/cochrane/clcentral/articles/047/CN-00779047/frame.html.
  40. 40. Jewkes R, Nduna M, Levin J, Jama N, Dunkle K, Puren A, et al. Impact of Stepping Stones on incidence of HIV and HSV-2 and sexual behaviour in rural South Africa: cluster randomised controlled trial. BMJ. 2008;337(7666):391–5.
  41. 41. Thurman TR, Kidman R, Carton TW, Chiroro P. Psychological and behavioral interventions to reduce HIV risk: Evidence from a randomized control trial among orphaned and vulnerable adolescents in South Africa. AIDS Care—Psychological and Socio-Medical Aspects of AIDS/HIV. 2016;28:8–15.
  42. 42. Devries KM, Knight L, Child JC, Mirembe A, Nakuti J, Jones R, et al. The Good School Toolkit for reducing physical violence from school staff to primary school students: a cluster-randomised controlled trial in Uganda. Lancet Global Health. 2015;385:e378–86.
  43. 43. Harrell MB, Arora M, Bassi S, Gupta VK, Perry CL, Srinath Reddy K. Reducing tobacco use among low socio-economic status youth in Delhi, India: outcomes from Project ACTIVITY, a cluster randomized trial. Health Education Research. 2016;31(5):624–38.
  44. 44. Ross DA, Changalucha J, Obasi AIN, Todd J, Plummer ML, Cleophas-Mazige B, et al. Biological and behavioural impact of an adolescent sexual health intervention in Tanzania: a community-randomized trial. AIDS. 2007;21(14):1943–55. pmid:17721102
  45. 45. Decat P. Addressing the unmet contraceptive need of adolescents and unmarried youth: act or interact learning from comprehensive interventions in China and Latin America: Ghent University; 2015.
  46. 46. Okonofua FE, Coplan P, Collins S, Oronsaye F, Ogunsakin D, Ogonor JT, et al. Impact of an intervention to improve treatment-seeking behavior and prevent sexually transmitted diseases among Nigerian youths. International Journal of Infectious Diseases. 2003;7(1):61–73. pmid:12718812.
  47. 47. Church D, De Asis MA, Brooks AJ. Brief group intervention using emotional freedom techniques for depression in college students: a randomised controlled trial. Depression research and treatment. 2012;2012:257172. pmid:22848802
  48. 48. Perry CL, Stigler MH, Arora M, Reddy KS. Preventing tobacco use among young people in India: Project MYTRI. American Journal of Public Health. 2009;99(5):899–906. pmid:19299670.
  49. 49. Devries K, Kuper H, Knight L, Allen E, Kyegombe N, Banks LM, et al. Reducing Physical Violence Toward Primary School Students With Disabilities. Journal of Adolescent Health. 2018;62(3):303–10. pmid:29217214. Language: English. Entry Date: 20180227. Revision Date: 20180227. Publication Type: Article.
  50. 50. Singhal N, Misra A, Shah P, Gulati S. Effects of controlled school-based multi-component model of nutrition and lifestyle interventions on behavior modification, anthropometry and metabolic risk profile of urban Asian Indian adolescents in North India. European journal of clinical nutrition [Internet]. 2010; 64(4):[364–73 pp.]. http://onlinelibrary.wiley.com/o/cochrane/clcentral/articles/428/CN-00762428/frame.html.
  51. 51. Ssewamala FM, Han CK, Neilands TB. Asset ownership and health and mental health functioning among AIDS-orphaned adolescents: findings from a randomized clinical trial in rural Uganda. Social Science & Medicine. 2009;69(2):191–8 8p. pmid:19520472. Language: English. Entry Date: 20100129. Revision Date: 20150711. Publication Type: Journal Article.
  52. 52. Kim CR, Free C. Recent evaluation of the peer-led approach in adolescent sexual health education: a systematic review. Perspectives on Sexual and Reproductive Health. 2008;40(3):144–51. pmid:18803796
  53. 53. Tolli MV. Effectiveness of peer education interventions for HIV prevention, adolescent pregnancy prevention and sexual health promotion for young people: a systematic review of European studies. Health Education Research. 2012;27(5):904–13. pmid:22641791
  54. 54. Carson KV, Brinn MP, Labiszewski NA. Community interventions for preventing smoking in young people. The Cochrane Database of Systematic Reviews. 2011:CD001291. pmid:21735383
  55. 55. Wiehe SE, Garrison MM, Christakis DA, Ebel BE, Rivara FP. A systematic review of school-based smoking prevention trials with long-term follow-up. Journal of Adolescent Health. 2005;36(3):162–9. pmid:15737770
  56. 56. German D, Sutcliffe CG, Sirirojn B, Sherman SG, Latkin CA, Aramrattana A, et al. Unanticipated Effect of a Randomized Peer Network Intervention on Depressive Symptoms among Young Methamphetamine Users in Thailand. Journal of Community Psychology. 2012;40(7):799–813. EJ990178.
  57. 57. Hawe P, Shiell A, Riley T. Theorising interventions as events in systems. American Journal of Community Psychology. 2009;43:267–76. pmid:19390961
  58. 58. Bonell C, Fletcher A, Morton M, Lorenc T, Moore L. Realist randomized controlled trials: A new approach to evaluating complex public health interventions. Social Science & Medicine. 2012;75:2299–306.