Forest school INterventions for Children’s Health: a feasibility cluster randomised controlled trial to compare Forest School versus usual indoor classroom-based curriculum activity with KS2 children: the FINCH protocol

Background

Forest School is an English name developed from the rich tradition of Scandinavian ‘Friluftsliv,’ literally meaning free air life⁶. Within Scandinavia there are a variety of interventions developed from this ethos including ‘skovegrupper’ (forest or wood groups), ‘naturbørnehaver’ (nature kindergartens) and ordinary early years settings that use the outdoor area they have available. These approaches can be distinguished from outdoor education, which often starts with an issue, agenda, or problem for children to investigate. Forest School approaches are led by the child’s interests, within a loose skills framework with an ethos summed up by one Forest School practitioner as “..we follow what the children point out first, and set challenges”⁷.

While Forest School interventions has been the subject of several recent systematic reviews^4,5, there have been no randomised controlled trials conducted, and evidence is limited with respect to its contribution to mental health and wellbeing benefits⁸. However, a large body of research suggests that nature-based interventions can be an effective means of supporting CYP’s mental health^9–12. Nature connectedness, which refers to an individual's subjective sense of their relationship with the natural world, has been identified as a key concept in regulating emotional and mental health. Individuals who are more connected with nature are usually happier in life and more likely to report feeling that their lives are worthwhile¹³. Sella et al.¹⁴ reviewed the literature on the influence of Forest Schools on the mental well-being of preschool children and found positive impacts in a wide range of variables that promote child health and development. However, they concluded that more evidence is needed because of methodological weaknesses across the reviewed studies. Evidence suggests that COVID-19 has widened the inequality gap in this respect, and children from ethnic minority backgrounds and low-income households are less likely than children in more affluent areas to experience the full benefits of access to nature and green space¹⁵.

Forest School is a complex intervention, and there is no agreed model of transformational processes or theory of change. Previous studies have highlighted some potential pathways to improving mental health and well-being, including providing nurture, time, and space away from school as well as connection to the rest of nature¹⁶. Our proposed program allows for iterative cycles of testing, development, and refinement of Forest School as a mental health and well-being intervention in the school environment. In partnership with our Patient and Public Involvement (PPI) group/members/co-applicants and using the current literature, we have developed an initial logic model and underpinning program theory to aid us in better understanding the likely mechanisms of action and pathways to impact mental health and wellbeing. We will seek to refine this model at the end of this study.

There are several training centres and packages offered through national bodies (e.g., the Forest School Association, FSA). Regionally, training has been provided by various providers for teachers/professionals about the skills required to organise and deliver outdoor activities in line with the nature-based pedagogy of Forest School (e.g., Nature Friendly Schools and Creative Outdoor Learning Award). Our Patient and Public Involvement (PPI) work indicates that schools are delivering Forest Schools in line with nature-based pedagogy principles and often use a set structure regarding frequency, timings, and activities. However, the delivery of Forest Schools is often not as prescriptive as some of the training providers outline, that is, the FSA. Therefore, despite widespread implementation, evidence about optimal delivery methods for Forest Schools and their impact on mental health and emotional well-being is scarce.

This study aims to explore the acceptability and feasibility of the delivery of Forest Schools, assess the feasibility of trial processes, establish key parameters to inform a definite trial, and produce a manualized toolkit. If the outcomes of this study meet our feasibility progression criteria, we will seek to progress this research into a definitive trial.

Study design

We report this protocol in line with the SPIRIT 2025 schedule of items to be addressed in a randomized trial protocol (a copy of the completed checklist can be found at: https://doi.org/10.1186/ISRCTN87263624). In accordance with this checklist, we have included a structured summary of the planned trial in our online repository (https://doi.org/10.1186/ISRCTN87263624).

We will conduct a feasibility cluster randomised control trial (RCT) of a Forest School intervention with 200 children in Key Stage 2 across eight schools across Hull, East Yorkshire, and North Yorkshire (England) with an embedded process evaluation to evaluate the quality and fidelity of intervention delivery. At the end of the study, focus groups will be used to refine the logic model and optimise the intervention. A patient and public involvement (PPI) group of children and parents/caregivers will meet periodically throughout the study to ensure input from those with lived experiences.

The trial was registered in ISRCTN (The United Kingdom’s Trial Registry). Clinical Trials Registration Number ISRCTN87263624. ISRCTN - ISRCTN87263624: Forest school research. This study was registered on the 11th of September 2024.

The full protocol is available on the NIHR website (https://fundingawards.nihr.ac.uk/award/NIHR157698. A detailed statistical analysis plan will be stored according to the York Trials Unit (YTU) standard operating procedures and guidance documents within the trial master file and are available upon request.

Ethical approvals

The study received ethical approval from the University of York Department of Environment and Geography. Reference DEGERC/Res/12072024/1. Any amendments to the protocol will be submitted first to NIHR by email for their approval and then to the Department of Environment and Geography. If an amendment is substantial, then we will also update the Clinical Trials Registry with new information.

Research questions

There are two research questions for the study:

Aims

Objectives

Patient and Public Involvement (PPI)

We have two experienced PPI leaders in the research team. The PPI Lead role will include developing and shaping the PPI plans with public contributors, including our collaborators Rewilding Youth Hull, and setting and refining the overall PPI strategy as the project progresses. Collaborators include individuals with specific expertise in delivering the Forest School and supporting the CYP.

Our CYP panel includes approximately 10 children (aged 7–11) and their parents/guardians. Children will have attended creative sessions facilitated by staff from the Rewilding Youth Hull, separate to their parents with both groups, and then come together at the end. Sessions are to be held in the ‘roundhouse’ at Rewilding Youth Hull, which is a special round building with a firepit inside, to provide a green setting for activities. In line with NIHR guidance and as suggested by the CYP, we will appropriately remunerate children and parents for their time using vouchers. We will hold eight sessions throughout the grant term (September 2024–June 2026) with initial sessions focusing on providing training to young people on what research is and developing creative patient information sheets/initial communications. Six sessions will be undertaken when the research is up and running to share the results and ask for feedback. Two sessions will be held at the end of the study (June 2026) to examine the creative means of dissemination.

The opportunity to join the panel will be shared widely across a variety of platforms and services, including but not limited to Humber teaching NHS FT (Youth Forum and Recovery College), Rewilding Youth Hull, Child Orientated Mental Health Innovation Collaborative (COMIC) PPI group, local authority contacts (Mental Health Support Team manager) and local community groups that meet the needs of ethnically diverse communities.

In addition to the CYP and parent panel, we will ensure that we hold initial open sessions before beginning research at any school site, inviting all parents/guardians, teachers, staff, and governors. We will ensure that at each session delivered with schools/parents/caregivers, they are given brief training on the research protocols and involvement to ensure that they feel their input is valued.

Forest school intervention

Definition: The intervention can be described as a non-classroom-based timetabled session of child-led exploration and play in an outside space encouraging connection with and exploration within nature. We have used existing best practices and definitions, looking at current models of Forest School delivery within schools (FSA), Nature Friendly Schools, Creative Outdoor Learning Award, and PPI input (PPI Leads/workshops/schools) to define what Forest School means in the context of this feasibility study. We have defined the minimum standards that all schools must ensure are included as part of the Forest School sessions:

Physical materials to be used as part of the intervention will vary depending on the outdoor space available, but commonly used materials will be natural features in school grounds, including trees, bushes, grassy areas, sticks, and stones. Teachers also receive a list of resources that would be helpful in running sessions. This will be prepared by our experienced Forest School teachers and will include items such as tarpaulin, rope, potato peelers, pots, and pans. An activity manual and slides developed for delivery at the Forest School training session will be available to schools in the intervention group and, following the trial, the control schools. At the end of the trial, this manual was adapted and developed into a workbook following additional information being added as a result of the observations, workshops, and interviews. Both the control and intervention arms will receive a copy of the Forest School workbook as an additional benefit of taking part.

Rationale and goals of the FINCH intervention

The intervention will be underpinned by existing and established frameworks around Forest School that characterise seven core areas related to fire skills, using tools, navigation, cooking and growing food, den building and knots, nature appreciation, and personal and social skills. Within these core skill areas, participants will be given opportunities to explore specific activities with the Forest School lead teachers and assistants to adapt these to learners’ interests, abilities, and needs. Examples may include supporting a child with fine motor skill difficulties in using tools or providing modifications to an activity, such as a quiet space for a child to work away from the group. Sessions are not prescriptive but need to include the core skill areas across the school term of delivery to ensure adherence to minimum standards. As the Forest School sessions are child-led, the teachers will adapt the lesson as much as possible around the needs of the children in their class (for instance, different activities for children who struggle to engage or for those who need more support). The teachers will tailor the Forest School experience around what the children engage most with.

Materials and mode of delivery

Our collaborators, PPI work, and existing Forest School delivery principles informed us of the materials and mode of delivery to be used in this study. Our collaborators had significant experience in applying these principles in practice. Sessions will take place at least two timetabled hours each week for one term (Spring or Summer), which equates to 12 sessions. A minimum of 10 out of the 12 sessions needed to be delivered, allowing for unforeseen circumstances such as staff illness and extreme weather. Splitting sessions into shorter time frames to account for unforeseen circumstances will also be considered appropriate, that is, 2 × 1-hour lessons instead of 1 × 2-hour sessions. Sessions will be delivered by existing staff within schools (headteachers, teachers, teaching assistants) who have previously received a specific core level of relevant training in Forest School delivery, including FSA Level 3, Nature Friendly Schools training, Creative Outdoor Learning Award, and/or at least five years’ experience in delivering nature/outdoor-based play/learning to account for skilled individuals with backgrounds such as Brownies/Scouts. While we aim to make this an inclusive feasibility study, PPI input suggests that schools without any prior experience of outdoor or nature-based interventions may find it challenging to deliver the Forest School model effectively. Therefore, we must balance inclusivity with the practical demands of a small feasibility cluster RCT.

There will be a minimum adult to child ratio of 1:9 and those with Special Educational Needs and Disabilities (SEND) will be supported by teaching assistants and volunteers. At the initial open sessions at each school, we will invite volunteers, offering continuing professional development for existing staff, such as midday supervisors and parents. These volunteers can potentially support the delivery of the intervention sessions, helping to increase the adult-to-child ratio.

Although there is no formal monitoring plan for the FINCH trial, we will adopt a risk-based monitoring approach, and the core study team will hold weekly meetings where we will discuss the progress of the trial and any issues with trial conduct or data collection, which may affect the integrity of the data. The study will be monitored on an ad hoc basis, in line with the particular needs of the trial. We have completed and signed a Data Protection Impact Assessment where we identified various risk factors associated with the study and how to minimize these; we will continuously hold our conduct of the study to a high standard and monitor our activities against these criteria. We will use our observations and reflections to design a comprehensive monitoring plan and proceed with a full trial.

Control arm

Control schools will be undertaking the usual indoor classroom-based curriculum activity during the terms when intervention schools are delivering Forest School. These activities were documented during the process evaluation. This comparator was chosen as we wanted to see if the Forest School has benefits over and above what currently happens in the classroom. After the study period, the control arm schools are welcome to start implementing Forest School, and the research team will be on hand to provide any guidance or support to allow them to do so. The community of practice sessions, in which all schools are invited to attend at three time points during the term, allows the control schools to interact with the intervention schools that are currently trialling Forest School and receive guidance and advice. These meetings were also attended by a member of the core Research Team and a member of the study team, who is a qualified Forest School practitioner. These sessions should put them in good place to successfully implement the Forest School if they choose to do so. No specific harm is anticipated, but a risk and adverse event process are in place.

Participants

The study is a multi-site study that will take place in eight primary schools across the East and North Yorkshire. We will work with each school to select a KS2 class as a part of the study. This decision will be made by the teachers based on the practicality of delivery and their previous experience in delivering outdoor education and Forest School related activities. If possible, we will ensure that we have a range of KS2 classes (Years 3–6) to ensure variation in age groups. All children in the class will be invited to participate in ensuring equal access. We will involve children aged 7–11 (KS2) in participating schools, including those with special educational needs and/or physical disabilities. We will use a school study agreement and consent form with each school to clearly delineate the requirements for participation and hold an introductory meeting before starting. Due to the nature of the intervention, there will be no blinding of the participants, teachers, facilitators, outcome assessors, or data analysts.

Inclusion criteria

Exclusion criteria

As this is a feasibility study, we will not exclude schools unless they have no access to outdoor spaces of any type and are not practically able to run Forest Schools (e.g., the school does not have capacity, or no teachers are trained to deliver Forest Schools). We are keen to test the feasibility of delivery across a variety of outdoor spaces in recognition of the fact that this improves accessibility and diversity.

Recruitment

We will gather expressions of interest (EOIs) from schools, including the schools we have already contacted in the development of the application, and will look to include schools with a range of geographic regions situated within communities with differing levels of socio-economic deprivation, ethnically diverse, and with varying access to outdoor space to undertake Forest Schools. A poster and participant information sheet (PIS) will be available to schools, and this will be shared through email, social media platforms, and physically within meetings and with schools. The start date for recruitment was September 2024 and the end date was April 2025.

Once a school has officially joined the study, it will sign a school study agreement that will set out the study timescales and protocol requirements.

Consent processes

Opt-out criteria were used in this feasibility study. Parents or caregivers will be provided with the PIS and contact details for the study, and will be given the option to opt out of data collection. Parents/caregivers will be asked to return a signed ‘Parent/Carer Child Withdrawal’ form if they do not wish to share their child/children's data with the research team, and/or they do not wish themselves or their child or children to take part in any assessments or surveys and subsequent focus groups and interviews. This will not affect their children’s participation in Forest Schools.

The researchers obtaining consent for the qualitative interviews will have up-to-date Good Clinical Practice training, will be DBS-checked, and will have the appropriate skills and qualifications to obtain consent. Parents and children will be provided with a separate PIS for the interviews. A consent form will be used for qualitative research interviews to be completed by the parent/caregiver, and the researcher will check their understanding. Children will be asked to complete an assent form indicating that they are happy to be interviewed, and the researcher will clarify that they understand what is involved. Consent will not be obtained for the observations as permission for these is included in the school-study agreement. We do not have any formal procedures in place to obtain consent from adults or children who lack the decision-making capacity.

Data protection and participant confidentiality

Participants’ data will be anonymized and kept confidential. Participants will be assigned a unique ID that will be linked to their data. Parents will be allocated the same ID as their child so that their data can be linked. Paper questionnaires will be stored in a locked filing cabinet and any identifiable information will be removed before they are stored. Personal demographic information about the children (e.g., date of birth, Special Educational Needs and Disabilities SEND details, free school meals, pupil premium, etc.) will be collected using a pupil details spreadsheet. This will be a password-protected file stored on a secure university-approved server and will be anonymized before being sent for analysis. Only a limited number of people will be able to access participant data to ensure the smooth running of the trial, data entry, or analysis. After the trial, only anonymized data will be presented in any report or publication to protect the confidentiality of the participants. Information disclosed during the interviews will be treated with the strictest confidence. Participant data transferred to sponsors, co-investigators, and external parties will be anonymized and sent through university-approved file sharing systems wherever possible. Confidentiality of participant information is of the highest priority and will be maintained throughout the study.

In line with the 2018 General Data Protection Regulation and UK Policy Framework for Health and Social Care, 79 anonymized trial data will be securely archived by the University of York for a minimum of 10 years. Personal data of participants will be stored for up to three years after the study has ended for the purpose of disseminating study findings. It is unlikely that this will take longer than 12 months; however, to ensure that participants receive adequate and full information about the study after it has finished, additional time was allocated.

All information collected during the trial will be kept strictly confidential, as described above. Information will be held securely in paper and/or electronic format at the University of York. The University of York complied with all aspects of the 2018 General Data Protection Regulation and Data Protection Act 2018. Operationally, this will include obtaining explicit consent from study participants to record personal details including name, postal and email address, contact telephone numbers, and appropriate storage, restricted access, and disposal arrangements for their personal details. All participants will be informed of their rights regarding stored personal information, including erasure, rectification, and objection. All work will be conducted following the University of York’s publicly available data protection guidance which is publicly available (University of York, 2018).

Sample size

Sample size calculations were based on estimating the retention rates and standard deviation (SD) of the candidate primary outcome (Strengths and Difficulties Questionnaire). At least four clusters per group are recommended for pilot cluster RCTs, and we intend to randomize eight schools. An average of 25 children per school are anticipated, and we will include eight schools (i.e., 200 children). This will be equivalent to 70 children in an individually randomized trial (assuming an ICC of 0.1), and would be sufficient to allow a completion rate of 80% to be estimated within a 95% confidence interval of ±9%, which is in line with the sample size for estimating a reliable SD. We will recruit additional schools to go on a reserve list in case schools drop out before randomization or before they start the delivery of the Forest School.

Data collection

The following data will be collected:

The following outcome measures will be collected at Baseline, Week 12 (end of intervention), and week 24 (follow-up), and the mean change from baseline at each time point will be analyzed:

Primary outcome

Secondary outcomes

These measures were chosen because they are validated for use with young children and/or are the most appropriate for analysing natural environments.

Randomisation

In this cluster, exploratory, parallel-group RCT, schools will be randomized with a 1:1 allocation ratio by a statistician based in the (YTU) who is not involved in the recruitment of the schools. The staff involved in trial delivery and liaising with the schools will not have access to the allocation schedule, which will be stored in the University of York Secure Drive. Minimization using free school status (at or above national average/below), class (year 3 or 4/ year 5 or 6), and location (urban/rural) will be undertaken using the MinimPY software.

Trial processes

We will collect feasibility data to inform a future randomized controlled trial at the Forest School. In addition, we will collect primary and secondary outcome measures at three time points (baseline), initial follow-up (week 12), and final follow-up (week 24) for both groups (Consort Flow Diagram available Figure 2: https://doi.org/10.1186/ISRCTN87263624). The research assistant will support the facilitation of these measures remotely, by telephone or face-to-face, depending on the preferences of parents and teaching staff. PPI work has informed the selection of measures, and key considerations, such as parental burden and accessibility, have been considered.

Recruitment: How can we successfully recruit to the study? What is the best way to engage with the population in which school sites are involved?

Retention: Do schools and participants withdraw from the study? If so, why and how can we reduce the number of withdrawals?

Representativeness of participants: Demographic information will be collected to determine if the intervention is accessible to a diverse population. Age, sex (male/female/third sex), ethnicity (based on ONS categories), special educational needs and disabilities (children with EHC; diagnosis), and Index of Multiple Deprivation based on participant home postcode.

Data completeness: Do schools and CYP complete the outcome measures included.

Acceptability of trial processes and intervention: This relates to both the intervention and the research process, and will be assessed based on quantitative data of the school sessions carried out and qualitative interviews with participants.

The progression criteria for a definitive RCT will be based on a RAG-rating traffic light system: green (proceeding to RCT), amber (review RCT design and/or intervention components and delivery), and red (stop and reconsider the design and/or intervention components and delivery).

Analysis

Data on the number of schools and pupils approached, agreeing to participate, schools randomly assigned, schools receiving the intended intervention, completing the study protocol, and pupils providing outcome data will be summarised. The number of schools/pupils withdrawing from the trial, and where available, the reasons for withdrawal, will be summarized. For each data collection point, the number of non-responders was calculated, and participation rates were compared. We may also quantify the degree of clustering using ICCs (with 95% confidence intervals), but acknowledge that this may not be reliable owing to the small sample size²⁴. All data will be summarized descriptively as counts and percentages for categorical data, and means, SDs, median, minimum, and maximum for continuous data. Data will be descriptively summarized overall, by group, and within subgroups (SEND status/type). We will gather these data on SEND status to consider whether it will be feasible and useful to examine the subcategories for future main trials. The number of sessions delivered and attended is summarized as a measure of acceptance.

Patterns of implementation and fidelity

The process evaluation gathers data to establish how the intervention is delivered and whether this varies across schools (Objective 4). The intervention is flexible, with scope for adaptation by the school staff to suit the needs of learners and the context of delivery. Nevertheless, as reported, there are several core principles and minimum standards that must be adhered to in order to meet our definition of a Forest School. We will explore adherence to these principles via Forest School facilitator brief self-report checklists to be completed by the lead Forest School Facilitator after each session.

Quality of delivery and participant responsiveness observations

Quality of delivery and participant responsiveness will be assessed through a structured observation conducted by two members of the research team in two randomly selected Forest School sessions. We will develop a coding framework for structured observation in line with specialist guidance on the implementation and process evaluation of school-based interventions in school settings²⁸. Items will be developed to code indicators of delivery quality, such as facilitator interest and enthusiasm, preparedness, and participant responsiveness during the delivery of a session²⁹. Items coded to assess participant responsiveness will assess the extent to which pupils appear to be engaged and interested in intervention materials and activities. We will consult our PPI and advisory groups regarding the development of the coding framework.

We will establish reach and dose by using attendance registers and session facilitator checklists to determine the number and proportion of children who engage in at least one activity in at least four of the seven core Forest School areas and monitor the overall number of sessions delivered per school.

Semi-structured qualitative interviews: to explore acceptability, context and mechanisms of action

Qualitative interviews with two members of the school staff (headteacher and class teacher) at the control schools will explore the extent to which the Forest School is different from the existing provision (differentiation). We also aimed to understand how the delivery of the trial impacted control schools, especially those who have experienced the study design, including the study setup and data collection. We will also interview the intervention group teachers, see below for more details, including interview methods.

Population sampling

Qualitative data will be generated through semi-structured interviews. We will purposively sample and recruit interviewees representing the following stakeholder groups: Forest School facilitators (n=8; two per intervention school), wider school staff (n=8; one to two per intervention school), children (n=16; four to six per intervention school), and their parents/caregivers (n=16). The selection sampling of Forest School Facilitators will include the leading staff member of the Forest School sessions (this is likely to be the class teacher) and one member of the staff supporting the Forest School sessions (this is likely to be the class teaching assistant). Implementation data will be used to ensure that we capture the views of high/low-fidelity facilitators. Wider school staff will be sampled to provide a range of seniority and roles, including head teachers and teaching assistants or SEND staff. Children and parents/caregivers will be approached based on consent status and then selected and purposively sampled to generate variation in age, gender, socio-demographic group, school, and SEND status.

Interview process

Topic guides will be used to focus on discussions, and emergent/unforeseen issues will be explored as appropriate. The topics covered in the guide will include perspectives on the acceptability of Forest Schools, how and why the intervention might impact child outcomes, and whether the impact achieved is influenced by student characteristics, wider school contexts or other factors, any unintended, potentially harmful consequences, and the acceptability of collecting measures and trial processes. Separate topic guides will be created for each stakeholder group and informed by the Theoretical Framework of Acceptability³⁰, developed in consultation with our PPI and advisory groups.

Recruitment and consent: qualitative interviews

Parents/caregivers will be approached by schoolteachers using a Patient Information Sheet (PIS) to explain the purpose and process of the qualitative interviews. Children will automatically opt in unless their parent/carer completes an opt-out form to withdraw their child from selection. Parents or caregivers interested in participating in an interview must complete and return a permission-to-contact form, either to the school or directly to the research team via email. This will enable the research team to make contact and be selected for an interview. Both forms are attached to the PIS.

Interviews will be conducted in person (in school) or online depending on the interviewees’ preferences. Full parent/caregiver consent will be obtained from the children selected for an interview. Children will be asked to complete an assent form to indicate that they are happy to be interviewed once the research team has briefed them about the interview process and answered any questions that they may have. Children will be interviewed (for a maximum of 30 minutes) by two members of the research team during the school day in groups of four to six in a focus/discussion group supported by a member of the teaching staff. This will take place in an area in the setting of their Forest School sessions, such as around the fire circle, to encourage discussion and engagement. For parents/caregivers, full informed consent will be obtained before the interview, which will last between 30–45 minutes and be scheduled for a time and mode most convenient to them (e.g., face-to-face, Zoom). In line with the recommended guidelines for payment of study activities, parents/carers will be reimbursed with a £25 Love2shop voucher to give us their time and views.

Recording process

All the interviews will be audio-recorded and transcribed verbatim. Topic guides and interview procedures will be piloted prior to use and refined, as needed. Quantitative data on the context for delivery will be gathered via UKHab, while factors that are anticipated to affect engagement with and benefits of forest schools will be captured using the NCI and the outdoor learning skills progression tool. Collecting these data will allow us to pilot mediator analyses representing theorized mechanisms of action.

Qualitative analysis

Qualitative data will be uploaded into specialist software for analysis via qualitative content analysis (free text from checklists) and thematic analysis (interview data), following the steps outlined by Bager-Charleson and McBeath³¹. The findings will be sensitized to the Theoretical Framework of Acceptability, and context-mechanism-outcome configurations will be developed.

Assessment and management of risk

An adverse event is any unexpected effect or untoward clinical event affecting the participant (i.e., any unfavourable and unintended sign, symptom, or disease). The severity of these events is outlined below. Possible harm as a result of the study is expected to be minimal but will be monitored and recorded. Adverse events (AE) in this study may include the following:

•   Significant emotional distress.

•   Verbal abuse

•   Physical violence

•   Physical injuries that did not require hospitalization.

•   Allergic reactions not requiring hospitalization

All AEs will be assessed for seriousness and will be recorded as Serious Adverse Events (SAEs) if they

•   Result in death

•   Are life-threatening

•   Requires hospitalization or prolongation of existing hospitalization

•   Persistent or significant disability or incapacity

The adverse event reporting period for FINCH begins once the school is randomized and ends 24 weeks after the baseline data collection, that is, after the school is sent their final follow-up questionnaire. In this study, AEs and SAEs will only be recorded and reported if the event is

1. Suspected to be related to the research procedures (e.g., taking part in the forest school intervention, completion of follow-up questionnaires, participation in an observation or qualitative study)

The following events will not be recorded or reported:

•   Normal childhood illnesses which are unrelated to an aspect of taking part in the study

•   Hospitalization planned prior to study entry

•   Pre-existing conditions.

•   Death, for example, from an illness such as cancer or an accident, which is unrelated to participating in the study.

Teaching staff will monitor children using internal school procedures for safeguarding and risk, and any concerns arising because the study will be communicated to the PI and research team as soon as reasonably practicable. If participants have any issues, they will have contact details with the research team. We will put adaptations in place to ensure accessibility for those attending with disabilities, such as sensory impairment or mobility restrictions. We will develop a resource pack for mental health support for schools that they signpost if needed, such as appropriate charities and local CAMHS.

The coordinating site

The Humber Teaching NHS Foundation Trust will act as the main sponsor for this study and oversee the delivery of the study with the York Trials Unit. The York Trials Unit will be responsible for processing, analysing, and archiving data. The Humber Teaching NHS Foundation Trust and the York Trials Unit will be jointly responsible for the writing of publications and disseminating results.

Trial steering group

A Trial steering group will be held every 6 months. The trial steering group will be attended by the study leads, in addition to independent academics with specialist knowledge of trial delivery and data management. The trial steering group ensured that the study ran to the study protocol.

Study management group

A study management group will be held every month during the 20 months of the study. The study management group is made up of public contributors, academic co-applicants, and co-applicants from education and local authorities. The study management group will be responsible for ensuring that the study runs the protocol.

Patient & public involvement group

Our Children and Young Person (CYP) panel will include approximately 10 children (aged 7–12) and their parents/caregivers. Children will facilitate creative sessions separate from their parents, with both groups coming together at the end. Sessions are to be held in the ‘roundhouse’ at the Rewilding Youth Hull to provide a green setting for activities. In line with NIHR guidance and as suggested by the CYP, we will appropriately remunerate children and parents for their time using vouchers. We will hold eight sessions throughout the grant term, with initial sessions focusing on providing training to young people on what research is and developing creative patient information sheets/initial communications. Six sessions will be undertaken when the research is up and running to share the results and ask for feedback. Two sessions were held at the end of the study to examine the creative means of dissemination.

The opportunity to join the panel will be shared widely across a variety of platforms and services, including but not limited to Humber teaching NHS FT (Youth Forum and Recovery College), Rewilding Youth Hull, Child Orientated Mental Health Innovation Collaborative (COMIC) PPI group, local authority contacts (Mental Health Support Team manager), and local community groups that meet the needs of ethnically diverse communities.

In addition to the CYP and parent panel, we will ensure that we hold initial open sessions before beginning research at any school site, inviting all parents/guardians, teachers, staff, and governors. We will ensure that at each session delivered with schools/parents, they are given brief training on the research protocols and involvement to ensure that they feel their input is valued.