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The evolution from top-down intervention models to youth agency and participation
Across the included studies, a clear shift from older to newer studies was observed, as older publications presented traditional interventions led by experts, while newer publications presented approaches that put adolescents as active contributors to health promotion. Previous health programs14 relied on adults to identify priorities and then to conceive interventions for young people. In contrast, the reviewed studies involved more adolescents in identifying problems, creating solutions, and influencing and determining the content of implementation.
The YPAR studies provided the most significant examples of this transition. In the physical activity promotion projects described by Abraczinskas and Zarrett35 and Lindquist-Grantz and Abraczinskas,17 youth conducted research, used photovoice to capture and analyze social/environmental factors, and advocated. Similarly, in the study of Watkins et al.,36 the adolescents set the priorities and content of the intervention. This type of intervention was also implemented in the study by Hannay et al.,37 in which youth formulated research questions, collected data, interpreted the results, selected collective narratives, developed action plans, presented the results publicly, and advocated for policy changes. Other research models reflected this same transition toward youth-led approaches. The Community-based participatory research study of Livingood et al.38 also demonstrated a high degree of autonomy; the young people served as advisors, photographers, facilitators, analysts, and presenters. Marco-Crespo et al.39 also involved young people who collected data, conducted interviews, reflected on the findings, formulated recommendations, and contributed to the planning of the intervention. Furthermore, in De Rosis et al.,40 youth participated in designing components of the intervention, developed communication strategies, disseminated health messages, presented their findings to policymakers, and served as health promoters among their peers. It was the same thing with Verloigne et al.,41 where adolescent girls selected physical activity-related behaviors to address, identified the barriers, generated ideas for interventions, designed promotional materials, and participated in the implementation. Beyond this transition from adult-led to participatory approaches, the selected studies also illustrate a progressive evolution in the depth of adolescents’ participation over time. Early participatory initiatives involved adolescents primarily in consultative roles and needs assessment and evaluation, where young people gave their opinions to inform the intervention design, but had limited influence in decision-making. More recent studies show a move towards a higher level of participation, characterized by shared decision making, by co-production and youth leadership throughout the entire research and intervention cycle. For example, Verloigne et al.41 involved female adolescents in the identification of priorities, in co-creation of intervention strategies and in the implementation of school activities, although researchers kept the responsibility of ensuring that the interventions remained evidence-informed. In contrast, the YPAR studies by Abraczinskas and Zarret35 and Lindquist-Grantz and Abraczinskas17 positioned adolescents as co-researchers who generated research questions, collected and analysed data, identified solutions and defended systemic changes. Similarly, Watkins et al.36 adopted a human-centered co-design, where adolescents actively shaped the intervention according to their own priorities and local context, while De Rosis et al.40 and Marco-Crespo et al.39 extended participation beyond intervention conception, involving adolescents in communication, dissemination, community engagement and interactions with policy stakeholders. Collectively, these studies suggest that health participatory promotion has evolved from a vision where adolescents were simple informants to recognizing them as legitimate partners, capable of contributing to the conception, implementation, evaluation, and long-term sustainability of health interventions. Nevertheless, a total transfer of control has hardly ever been observed, as adults and researchers continued to provide inputs and structure and methodological guidance.
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Co-creation as a methodological approach in adolescent health research
In all included studies, Co-creation emerged as a flexible methodology instead of a single intervention model. Adolescents collaborated with researchers and other stakeholders to develop contextually relevant solutions addressing movement behaviors and healthy lifestyles. Different participatory approaches were identified, including the YPAR, co-production, and co-creation frameworks. Despite methodological differences, common principles included shared decision-making, iterative development, dialogue among stakeholders, and valuing adolescents’ experiential knowledge. The following studies (De Rosis et al.40; Livingood et al.38; Verloigne et al.41; Watkins et al.36) were coded as “Co-creation” as a primary theme.
De Rosis et al.40 involved adolescents in designing, implementing, and evaluating the intervention in collaboration with professionals who served as facilitators. Livingood et al.38 similarly used Community-based participatory research with Youth Advisory Board, which incorporated youth perspectives into program development and community action processes. Watkins et al.36 highlighted the value of sustained collaboration with adolescents throughout the development process. Stakeholders collaboratively identified the issues and developed refined program strategies through a series of iterative workshops. Their findings showed that adolescents provided insights that improved intervention acceptability and ensured that health messages reflected young people’s priorities and lived experiences. In Verloigne et al.,41 girls from vocational and technical schools jointly designed and implemented the physical activity interventions with researchers. Each school created its own intervention, reflecting local needs and contexts. However, the study also showed that substantial researcher facilitation was necessary to guide the process to ensure that the interventions were evidence-based.
In a similar vein, Abraczinskas and Zarrett35 engaged youth in conducting research, using photovoice, analyzing data, and advocating alongside adult partners/facilitators, who provided support instead of directing decisions. Likewise, Lindquist-Grantz and Abraczinskas17 positioned YPAR itself as a health intervention approach and demonstrated its application to both physical activity promotion and suicide prevention. In both contexts, young people served as co-researchers and agents of change throughout the investigation, analysis, and action processes.
Marco-Crespo et al.39 also used a participatory approach in which adolescents contributed to the development and evaluation of a Chagas disease prevention programme. Young participants took part in workshops, interviews, reflection exercises, community exploration, data collection, and collective analysis, illustrating how co-research can increase contextual relevance and cultural appropriateness. Extending this approach, Hannay et al.37 demonstrated another form of participatory engagement by involving adolescents and community stakeholders in health promotion activities, reinforcing the importance of collaborative partnerships in intervention development. Participation was structured according to the principles of Photovoice: participants documented the community’s strengths and concerns through photography, engaged in dialogue, identified themes, and communicated their findings to policymakers to promote change.
Although adolescents were consistently positioned at the center of the co-creation process, the successful interventions relied on the complementary contributions of multiple stakeholders, each playing distinct yet interconnected roles. Researchers act mainly as facilitators, methodology experts, and capacity builders rather than solo decision makers, providing training, ensuring scientific rigor, supporting data collection and analysis, and maintaining fidelity to health promotion objectives (Abraczinskas & Zarrett35; Lindquist-Grantz & Abraczinskas17; Verloigne et al.41; Watkins et al.36). Community stakeholders – including teachers, school staff, health professionals, youth workers, community organizations and policymakers – contributed by facilitating access to participants, providing contextual knowledge, supporting the implementation and creating opportunities for integration and the sustainability of youth-generated solutions (De Rosis et al.40; Hannay et al.37; Livingood et al.38; Marco-Crespo et al.39). However, the level of involvement varied across studies, going from consultation and logistic support to active planning, collaboration, implementation, and dissemination of the intervention. Rather than replacing professional expertise, co-creation redistributed responsibilities among stakeholders, with adolescents contributing experiential knowledge and contextual insights, researchers ensuring methodological quality, and community partners facilitating the translation of co-creation solutions into practice. This complementary distribution of roles emerged as a defining characteristic of operationalizing co-creation within adolescent health promotion.
Across the included studies, several practical challenges were consistently reported. Keeping adolescents engaged required adaptation and flexibility regarding local schedules, as well as continuous facilitation by adults. Furthermore, researchers had to adopt different roles, such as moderators or trainers, to provide organizational support, instead of acting solely as traditional experts. Balancing adolescents’ autonomy with the need to preserve scientific rigor emerged as a recurring challenge. Additionally, contextual factors such as organization readiness, staff commitment, school support and available resources, strongly influenced implementation success. In general, the evidence suggests that co-creation is not a single, uniform method but rather a continuum of participatory approaches that requires a considerable investment in facilitation, adaptation and relationship-building. Ultimately, successful implementation depends not only on involving adolescents, but also on creating supportive environments that enable meaningful participation.
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The application of systems thinking to complex health behaviors
Systems-oriented perspectives were evident across several studies; however, the robustness of their application varied substantially. The included studies demonstrated increasing acknowledgement that adolescent health behaviors are shaped by complex and interconnected systems rather than by isolated individual factors. Systems thinking terminology was not defined or used in a systematic manner across all studies; nevertheless, many interventions incorporated ecological principles and acknowledged the interactions occurring between individuals, social environments, organizations, and communities.
The strongest application of systems thinking was observed in Abraczinskas and Zarrett35 and Lindquist-Grantz and Abraczinskas.17 Both studies explicitly described YPAR as operating simultaneously on youth development and the socioecological systems surrounding adolescents. There was an explicit socioecological and developmental systems orientation. The papers repeatedly discuss impacts across individuals, peer groups, schools, healthcare organizations, and communities. Also, first-order versus second-order change, structural inequities, multi-level influences feedback loops and sustainability through ongoing youth input. As noted in the research, “the study highlighted YPAR as an intervention strategy with the potential to produce a developmental cascade where changes in one domain or system influence another domain or system and there is a cumulative effect over time” Lindquist-Grantz and Abraczinskas.17 To achieve this, Lindquist-Grantz and Abraczinskas17 integrated Positive Youth Development theory with Bronfenbrenner’s ecological framework, describing adolescent development as occurring through reciprocal interactions across systems. Through this approach, youth gained confidence, empowerment, and research skills, while the participatory processes themselves stimulated continued community action and system-level change.
Evidence of these systemic feedback loops was also apparent in the work of Abraczinskas and Zarrett.35 In their study, youth recommendations led programme staff to establish ongoing mechanisms for adolescent input. This successful implementation of youth-proposed changes created a self-reinforcing cycle - and a permanent feedback loop - in which increased empowerment and participation generated organizational change, which in turn supported continued, meaningful youth engagement.
Verloigne et al.41 identified schools as critical contexts for influencing behaviors related to physical activity. Rather than implementing a single standardized intervention, each school developed context-specific strategies, acknowledging that small changes within local systems could lead to broader behavioral effects. However, the study also highlighted that the success of the implementation depended on the organization’s support and the existing school culture. Expanding this perspective to health care, Livingood et al.38 acknowledged that adolescents with chronic conditions interact with multiple systems simultaneously, including health services, families, and community organizations. Their participatory action approach sought to improve these connections by integrating the perspectives of patients and their families into the services delivered. As well, De Rosis et al.40 viewed a healthy lifestyle as the result of interactions between adolescents, professionals, schools, and communities. Although systems thinking terminology was mainly implicit, their process of co-production acknowledged that behavior change stems from interpersonal relationships and contextual influences, rather than individual knowledge alone. Marco-Crespo et al.39 similarly demonstrated how community participation could work as a leverage point for disease prevention, by connecting the efforts of adolescents, families, and local interested parts to control the Chagas disease. This approach acknowledged that a sustainable change demands action beyond individual participation. Alternatively, Hannay et al.37 and Watkins et al.36 focused primarily on participatory involvement and in community-level evaluation, instead of explicit systems concepts. However, both studies still acknowledged the importance of the local context and the influence of social environments on adolescents’ health behaviors.
Overall, the findings suggest that systems thinking within adolescent health co-creation interventions in socially disadvantaged settings was predominantly achieved through ecological perspectives, iterative feedback mechanisms, and an acknowledgment of the interdependences between adolescents and their environments. Explicit systems mapping techniques were rarely utilized, and none of the included studies mentioned the formal use of causal loop diagrams or system dynamics models. Instead, systems thinking was largely embedded implicitly within participative processes and in socioecological frameworks.
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Evaluation frameworks and methodological challenges in co-created interventions
Across the included studies, the evaluation approaches went beyond the traditional paradigm of randomized controlled trials (RCTs), acknowledging that co-creation interventions are complex, context-dependent adaptive processes. The evidence suggests that conventional efficacy designs alone are insufficient to capture the mechanisms by which participatory interventions influence adolescents’ health outcomes.
Verloigne et al.41 used a case-control design, but they emphasized that each school created its own intervention, which means each context’s development is based on its own co-creation activities. There is a tension between methodological rigor and participative flexibility. Similarly, Abraczinskas and Zarrett35 utilized a mixed-method triangulation design without group control. Instead of focusing exclusively on behavioral outcomes, they measured empowerment subscales, participatory behavior, sociopolitical skills, and systems changes. Their study suggests that while causal inference regarding physical activity improvements is limited, youth-led changes to increase physical activity access have the potential to decrease health disparities by generating unique solutions likely missed when adults intervene alone. Ultimately, these findings demonstrate that process outcomes and systems changes represent meaningful indicators of success in their own right. Lindquist-Grantz and Abraczinskas17 further explicitly identified the need for a more rigorous evaluation of YPAR. At the same time, they emphasized that participative interventions produce effects across various socioecological levels. They recommended that evaluated outcomes should extend beyond individual behavior change to include youth development, community-level impacts, and long-term environmental change. The authors also underscore that process evaluation is essential because YPAR involves three interactive partnerships: researcher–community, researcher–youth, and community–youth. Similarly, Watkins et al.36 highlighted that the evaluation of coproduction must account for both final outcomes and the implementation process itself. Their human-centered co-design study examined participant engagement, stakeholder experiences, and intervention acceptability, alongside the contextual factors that facilitated or constrained program development, rather than relying solely on traditional effectiveness indicators.
Other studies reinforced the value of mixed-method and process-oriented evaluation approaches. Hannay et al.37 combined the Photovoice method with focus groups to assess both the results of the community assessment and the adolescents’ involvement, illustrating how participatory methods can simultaneously generate data and serve as mechanisms for empowerment. Marco-Crespo et al.39 used YPAR and other evaluation approaches to analyze both the learning processes and the community-level implications of a Chagas disease prevention program, demonstrating a dual focus on both the implementation of the intervention and its outcomes. Likewise, De Rosis et al.40 evaluated a co-developed health promotion initiative using both process and outcome indicators, analyzing adolescents’ experiences, involvement, and perceptions, along with health-related outcomes. Among the included studies, Livingood et al.38 provided the clearest application of an implementation science framework, by using a multi-level ecological approach involving a community coalition, a primary health care network, and youth services – “Three-Tiered Approach to Community”. This approach enabled consideration not only of intervention effectiveness but also of its scalability, sustainability, and potential public health impact.
Overall, the included studies indicate that co-created adolescent health interventions in socially deprived settings require evaluation approaches that accommodate adaptation and contextual variation, multiple levels of impact, non-linear pathways of change, stakeholder experiences, implementation processes, and sustainability considerations. Collectively, the evidence supports a shift away from exclusively RCT-based models toward mixed-method, process-oriented, and implementation-focused evaluation strategies. None of the included studies reported the use of realist evaluation or SUPER-AIM. While this may partly reflect the fact that SUPER-AIM is a recently developed framework that has not yet achieved the widespread adoption of RE-AIM,16 the findings nevertheless suggest that both approaches remain underutilized in adolescent co-creation research.
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Issues of sustainability, scalability, and contextual transferability
A recurrent finding across the 8 included studies was that the long-run success of co-creation interventions depended less on the intervention itself and more on the extent to which local systems, organizations, and interested parties were willing and able to sustain the participative processes beyond the project’s formal period. Instead of facing sustainability as a continuation of a specific intervention, many studies conceptualize it as maintaining the adolescents’ engagement, stakeholders’ partnerships, and mechanisms for ongoing adaptation and decision-making.
The strongest evidence about sustainability came from the YPAR studies. Abraczinskas and Zarrett35 reported that youth-generated recommendations led to organizational changes within after-school programs and that one site established an ongoing feedback mechanism allowing adolescents to continue participating in program decision-making after the intervention ended. The authors argued that sustainability was facilitated by institutional support and the integration of youth voice into existing organizational structures. Similarly, Lindquist-Grantz and Abraczinskas17 emphasized that participatory processes must be sustained beyond individual projects and that evaluations should examine the ongoing capacity of both young people and stakeholders to engage in iterative cycles of research and action: “sustainability of participatory processes should be planned from the outset and examined within the evaluation, especially the continued capacity of youth to engage in cycles of research and action as a means to affect long-term outcomes, and the capacity of stakeholders to continuing supporting youth in these endeavors”. Their conclusions suggested that sustainable impact depends on developing youth leadership, strengthening community partnerships, and incorporating participation into local systems, rather than treating it as a temporary component of intervention.
Several studies have highlighted the challenges of scalability when interventions are intentionally adapted to local contexts. Verloigne et al.41 demonstrated that every school that participated in the study developed a singular intervention of physical activity through co-creation, reflecting the circumstances and local priorities. This increased the relevance and contextual acceptability but also created some challenges regarding replication and standardization. The authors proposed a model that local interventions can generate transferable lessons, keeping flexibility between different contexts. These findings suggest that scalability in co-creation interventions can occur through the dissemination of the principles and processes, instead of replication of identical intervention components. The importance of context adaptation was also clear in Watkins et al.,36 where the co-design, human-centered participatory process was specifically adapted to a rural school environment. The study evidenced how the development of the intervention was molded by the local resources, school structures, stakeholders’ priorities, and community characteristics. The authors argue that this approach produced a contextually relevant and testable intervention prototype while strengthening campus - community partnerships that may support future implementation and sustainability.
The studies by Hannay et al.37 and Marco-Crespo et al.39 further reinforced the importance of local context. The former involved Latino adolescents in community evaluations through Photovoice and focus groups, where participants documented the community’s strengths and concerns, generating highly relevant results to their culture and environmental realities. Similarly, Marco-Crespo et al.39 used the youth participatory evaluation to guide a Chagas disease prevention program in Ecuador, demonstrating how community involvement and cultural relevance increased the credibility and acceptability of the intervention activities. Both studies suggested that interventions are more likely to succeed when local populations actively contribute to the identification of priorities and the elaboration of solutions.
Livingood et al.38 addressed issues of transferability and sustainability in an indirect manner through Community - based participatory research approach. They involved youth, as members of the Youth Research Advisory Board, and included stakeholders interested in the community and the health area during the development of the intervention. The study focused on ensuring that the digital obesity prevention intervention reflected local needs, communication preferences, and implementation realities. The authors argue that this participatory development may increase the relevance, the acceptability, and the potential for future implementation of the intervention in vulnerable urban communities, although formal assessments of adoption, maintenance, scalability, or dissemination were not conducted. Similarly, De Rossis et al.40 observed that co-production promoted adolescent empowerment, autonomy, responsibility, and engagement, enabling participants to serve as healthy lifestyle promoters among their peers. The authors suggested that these participatory processes can trigger broader activation effects and community-wide dissemination, though notably, long-term sustainability beyond the project duration was not directly evaluated.
Across the studies, several factors emerged consistently as determinants of intervention success or failure in different contexts. Successful interventions were characterized by strong stakeholder involvement, organizational readiness, institutional support, flexibility for local adaptation, and significant youth participation throughout the entire process. On the other hand, sustainability was threatened when projects depended heavily on outside researchers, lacked long-term commitment, or did not establish mechanisms for continued youth engagement after the conclusion of the project.
