This scoping review  maps existing research literature that explores children’s participation as a component of interventions involving both schools and communities to improve health. The search was conducted in accordance with theoretical boundaries and working definitions identified from available literature reviews [7, 8, 11, 13, 14, 20–22] as well as previous work [3, 12, 23–26] as explained below.
In this review, we refer to an intervention as a “programme, service, policy or product that is intended to ultimately influence or change people’s social, environmental, and organisational conditions as well as their choices, attitudes, beliefs, and behaviour”  (p.452-453).
Prevention interventions in schools
Drawing from the Schools for Health in Europe network framework [28, 29], the term “schools” refers to all types of schools including nursery, primary and secondary, comprehensive, vocational, and specialised schools. Prevention interventions in schools could include all or some of the six components of a whole-school approach: healthy school policies, school physical environment, school social environment, individual health skills and action competencies, community connections, and/or health services.
Collaboration between school and local community
“Community” refers to the local community in which the school is anchored. Depending on the context it could be a village, district, or municipality; in other words, any territorial unit in which people have a collective sense of belonging and a shared identity [30, 31]. Collaboration between a school and the community entails elaborating and implementing a project relating to the early prevention of NCDs. The community includes a broad range of stakeholders, including parents, citizens, professionals and all types of public, private and civic organisations. The relationship between the school and the community may differ from one intervention to another, depending on the type of intervention .
“Stakeholders” refers to all the people involved in the process of intervention implementation. Children are the most important stakeholders because they are the focus, and comprise the prime target group, of interventions. Professionals from the education, health and social sectors as well as parents, policy-makers and other adults in the school and local community are also stakeholders and often comprise secondary target groups.
Active involvement of stakeholders
The involvement of stakeholders in the intervention, also called participation in the intervention, implies that everyone with a stake in the intervention has a voice and an active role in the development and/or implementation process, with more or less influence on decision-making. People (e.g., children, parents, professionals, volunteers, and politicians) are considered to have the needed skills to act in the process. The level of involvement was defined with reference to Mygind, Hällman and Bentsen , Carmel, Whitaker and George  and Hart  regarding the “Ladder of Children’s Participation”. Involvement ranging from representative to consensus levels was considered (see the Data analysis section for details).
When considering complex interventions, based on a holistic view of health, that involve multiple stakeholders at various stages in the process of development and implementation, it is imperative to define what will be explored in terms of outcomes, i.e., what nature of outcomes is considered and how they will be evaluated. With regard to outcomes, we incorporated a wide range of effects, including health-related effects at the individual level of the participating children, the effects on adult stakeholders, and organisational changes and effects on the school and/or community setting.
A scoping review
A scoping review can provide a relatively quick mapping of an area that is complex or that has not yet been subject to a comprehensive review. It maps the main sources and types of available evidence, as well as key concepts of emerging research areas . This approach is relevant because the context studied is that of emerging evidence. “The difficulty of conducting systematic reviews of public health interventions directly reflects the complexity of the interventions reviewed and the subsequent determination of effectiveness. Some of the key challenges in the public health field include the focus on populations rather than individuals, multi-component interventions, qualitative as well as quantitative approaches, an emphasis on processes of implementation, and the complexity and long-term nature of the interventions and outcomes”  (p.367–368). A range of study designs were included in this review to address questions beyond those relating to intervention effectiveness, and to generate findings that can complement those of clinical trials .
We collected information about research on interventions addressing different levels of involvement and the development of children’s and young people’s capacity to critically explore and improve their physical environments, as well as initiatives targeting social factors influencing physical activity and healthy eating at different levels, e.g., the family, school, community, and city levels . These interventions are based on a setting approach (i.e., school and community), and are designed to mobilise students and other local stakeholders involved in young people’s education and everyday lives.
The searches were conducted in October 2015. To identify relevant research-based evidence, a combination of several literature search strategies was used: electronic database queries, hand searching of key journals and consultation with experts and stakeholders. In addition, the reference lists of pertinent articles were checked for studies of relevance to the review. We reviewed papers in English, French, Portuguese, and Spanish. The focus was on empirical studies addressing children and young people’s involvement in health initiatives focused on physical activity and diet involving schools and communities. See Fig. 1 for the information sources and search terms.
Five selection criteria were applied. Included in the review were (1) empirical studies describing (2) a health intervention focused on diet and/or physical activity, (3) based on children’s and young people’s involvement that included (4) a relationship between school and local community, while (5) providing explicit information about the outcomes of the intervention on a structural, organisational and/or individual level. Papers in which one or more criteria were missing were not included.
A three-step selection process was applied. All search results (n = 3253) were included in a database, from which the first selection process was conducted by two researchers to determine the paper’s relevance for the review as assessed by title and abstract. Studies were excluded if the reviewers agreed that they did not meet the eligibility criteria (i.e., were not within the scope or contained insufficient information). Disagreements were resolved through discussion to reach consensus. Second, the selected articles (n = 24) were reviewed and assessed based on a full-text reading by two independent groups of two reviewers each, using a shared template to ensure internal validity. Papers for which there were no explicit references to participatory approaches and a school-community relationship were excluded. Third, the remaining papers were analysed by the two groups of researchers. The four reviewers then established the final sample, consisting of 12 papers.
Three external experts (professionals from the health and education sectors) from Denmark and France were given the opportunity to suggest additional references, to provide insights beyond those found in the literature and to lend a critical view on the relevance of the findings.
Descriptive information related to the study design and intervention design is available in the Additional file 1: Table S1. The analysis focuses on three types of intervention characteristics. Two of them relate to intervention design, namely the degree of children’s involvement and the nature of the school-community collaboration, while the third relates to intervention outcomes. The analytical approaches are described below for each analytical category.
Although there is a continuum of distinct definitions regarding children’s and young people’s influence and engagement, their levels of involvement were defined and applied in a deductive analysis. The categories in this review are inspired by Carmel, Whitaker and George’s  user-involvement spectrum—namely consultative, representative and consensus—and Hart’s  “Ladder of Children’s Participation”.
In the original work, there are three levels of participation. Only two were considered in this review, however, because the first (consultative) is characterised by children and young people solely providing and receiving information in relation to the intervention design, planning, implementation and/or evaluation processes. We do not consider this a genuine involvement of children and young people, since they are assigned and merely informed, while the school and/or community initiate and run the intervention.
The representative participation level is characterised by children and young people being consulted and informed, and providing suggestions to adult stakeholders regarding the initiative. They understand the process of implementation, their opinions are taken seriously, and they are informed as to how they have contributed to the final outcome. The suggestions provided by children serve to influence the adults’ decision-making; the children themselves do not directly act as decision-makers.
The participatory consensus level is characterised by children and young people taking responsibility for and influencing decisions relating to actions. Although the school and/or community may initiate the project, the decisions are shared with children and young people, whose wants and needs are articulated through an encouragement of their active involvement in the development process. Children and young people have real power and take part in designing, planning, implementing and/or evaluating the intervention.
The school-community relationship is categorised by three inductively defined levels of collaboration: (1) Shared activities, which refer to interventions with some degree of collaboration between schools and communities. Activities related to the intervention are present in both settings but without actual collaboration; (2) Collaboration, which refers to interventions with a high degree of collaboration in which either the school or the community takes the lead in developing and implementing the project. Actions may include partnership-building or communal initiatives; (3) Joint intervention, which refers to interventions based on a co-construction of the project throughout the process from design to implementation.
Complex interventions may result in a wide range of organisational outcomes and effects on stakeholders involved in the project. The included studies were categorised in relation to the reported effects on one or more aspects of three stakeholder groups: (1) Structural outcomes at the community/school level. These include institutional changes in the community/school organisation; (2) Outcomes related to adult stakeholders, e.g., empowerment of stakeholders; Finally, the third category includes (3) Outcomes directly related to children, e.g., health-related effects, knowledge, and motivation.