Table 1.

Eligibility criteria for inclusion of studies in the framework synthesis

	Inclusion	Exclusion
STAGE 1 CRITERIA: TITLE/ ABSTRACT SCREENING
Article type	Original research published in peer-reviewed academic journals	Conceptual or theoretical papers, opinion pieces, reviews
Population	Typically developing children or early adolescents with a mean age between 5 and 14 years AND/OR Adults with a role relevant to children in the school setting (e.g. teachers, yard duty supervisors, school administrators, school nurses, parents). The aim of the research must be to explore adults’ behaviour and/or perceptions in relation to children’s active play and/or risky play in schools	Children older or younger than the age range specified Children with a medically diagnosed condition e.g. asthma, autism, epilepsy, intellectual disability, immune disorder etc Adults’ perceptions of PE, active lessons, structured recess or children’s active play or risky play outside of school
Study setting	Elementary or middle school (or equivalent) settings	Before- or after-school programs, early childhood programs, high schools
Context	Recess: defined as “the non-curriculum time allocated by schools between lessons for youth to engage in leisure activities” ([68], p.3)	Structured classroom activity breaks, active lessons, physical education classes, outdoor education programs, outdoor learning
Condition	Active play or risky play: Active play: defined as “a form of gross motor or total body movement in which children exert energy in a freely chosen, fun, and unstructured manner” ([17], p.164) Risky play: defined as “thrilling and exciting forms of physical play that involve uncertainty and a risk of physical injury” ([53], p.22) In recognition of the wide variation in the literature for terms pertaining to children’s play, the following alternative terms were included: outdoor play, free play, unstructured play, physical activity during play, unstructured physical activity, child play, challenging play, and adventurous play	Structured-play, structured-recess programs such as walking interventions, teacher-organised recess activities
Research method	Original research employing at least one qualitative research method such as focus groups, observation, or walking interviews Mixed methods studies were included if data from the qualitative components could be extracted and analysed independently of the quantitative results	Quantitative research methods e.g. experimental, quasi-experimental, cross-sectional and cohort studies
STAGE 2 CRITERIA: FULL-TEXT SCREENING
Risk or safety outcome	Safety or risk-related finding or theme in relation to children’s active and/or risky play Risk: defined as “the effect of uncertainty (whether positive or negative) on objectives” [69] Safety: defined as “a state in which hazards and conditions leading to physical, psychological or material harm are controlled in order to preserve the health and well-being of individuals and the community” [70]. Notably this definition of safety includes safety from both physical and psychological harm	Study findings relating to safety and risk in schools that are not directly related to active play or risky play, such as: gun violence, soil or air pollution, microbial infections
STAGE 3 CRITERIA: 2ND FULL-TEXT SCREENING
Outcome data is contextually thick	Risk and safety findings must be contextually thick Contextually thick descriptions identify both an ‘issue’ (e.g. a risk or safety finding in play) and its context, and the context provides the social or cultural meaning to the issue, thereby aiding it’s symbolic importance and understanding [61]	Risk or safety findings are contextually thin, due to: 1. Scope: multiple conditions or setting domains investigated; 2. Outcome data reported too brief; 3. Method: Questionnaire within insufficient qualitative data; 4. Process evaluation reporting of intervention or outcomes with thinly described data; 5. Ethnographic reporting method where ‘findings’ cannot be differentiated from the remainder of the article; 6. Method: relevant data limited to children’s drawings without children's own explanation of meaning
STAGE 4 CRITERIA: 3RD FULL-TEXT SCREENING
Population: children	Children or early adolescents with a mean age between 5 and 14 years Studies where both children and adults were participants were included if data relating to child participants could be extracted and analysed independently of the adult participants	Adults with a role relevant to children in the school setting (e.g. teachers, yard duty supervisors, school administrators, school nurses, parents)