Dhital 2019.

Study characteristics
Methods	Study design: cluster‐RCT Study grouping: parallel group Cluster size: 80 children (mean) Study duration: 26 weeks
Participants	Inclusion criteria: adolescents studying in grades 6, 7, and 8 of the selected schools at the time of data collection; adolescents with written consent from themselves and their guardian without any known diagnosis of mental health problems Exclusion criteria: adolescent who refused to participate Age range: intervention group (n = 605): mean 12.9 (SD 1.3) years; control group (n = 615): mean 12.9 (SD 1.4) years Gender: 50% boys, 50% girls Intervention sample: 605 Control sample: 615 Main type of traumatic event: displacement Phase of humanitarian crisis: after the acute crisis (mortality was similar or less than what it was before the crisis) Type of humanitarian crisis: disasters triggered by natural hazards (earthquake)
Interventions	Intervention name: no specific name. Intervention described as a "teacher‐mediated school‐based intervention" Delivered by: para‐professionals (community workers): school teachers Format of therapy: face to face Number of sessions (total): 8 Type of control: school as usual Type of intervention context: school Type of promotion intervention: group level Description of the intervention: teacher‐mediated school‐based intervention, which falls under the second layer of intervention as outlined in Inter‐Agency Standing Committee (IASC) guidelines.
Outcomes	The cluster effects were controlled for all the school in the generalised estimating equations model Hope Outcome type: continuous outcome Reporting: fully reported Scale: Children's Hope Scale Direction: higher is better Data value: endpoint Acceptability (dropout from trial) Outcome type: dichotomous outcome Reporting: fully reported Data value: endpoint
Notes	Sponsorship source: this work was supported by the Grant‐in‐Aid for Challenging Exploratory Research from Ministry of Education, Culture, Sports, Science and Technology, and National Center for Global Health and Medicines, and Post‐ Disaster Health Promotion Project in Dhading from The Association of Medical Doctors of Asia in Tokyo, Japan. Country: Nepal Setting: 15 municipality secondary schools in the Dhading district Author's name: Rolina Dhital Institution: University of Tokyo Email: mjimba@m.u‐tokyo.ac.jp Address: Department of Community and Global Health, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The names of all schools were written in separate pieces of paper and folded into opaque envelops. Each pair of schools were grouped together and one school from each pair was randomly assigned to either group A or B. The groups were then randomly assigned as the intervention or control group through concealed allocation by the DEO. The unpaired school was also randomly assigned to either group through the methods mentioned above. As a result, the intervention group had eight schools, and the control group had seven schools."
Allocation concealment (selection bias)	Low risk	Quote: "The groups were then randomly assigned as the intervention or control group through concealed allocation by the DEO."
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Blinding was not done for the intervention because all schools were required to be informed about the intervention."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information provided.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rate intervention group: 7.6% (46 dropout out of 605 randomised participants); attrition rate comparison group: 16.9% (104 dropout out of 615 randomised participants).
Selective reporting (reporting bias)	Low risk	All measures described in the methods section of the article were also reported in the results. No trial protocol available but trial registered at ClinicalTrials.gov (NCT03387007)
Therapist qualification	Low risk	Quote: "the clinical psychologist provided two days of training on psycho‐social support for the school teachers. The training comprised eight sessions in total with one to two hours for each session."
Therapist/investigator allegiance	Unclear risk	No information provided.
Intervention fidelity	High risk	Intervention fidelity was not assessed. Quote: "the research team interacted with the teachers at 6 months follow‐up through focus group discussions (FGD) to understand their perspectives on the usefulness of the training and the activities they conducted after the training."
Other bias	Low risk	No other sources of bias can be detected. Cluster‐RCT risk of bias extension 1. Recruitment bias; the recruited population belonged to the same catchment area (low risk of bias) 2. Baseline imbalance; cluster balance was maintained after randomisation (low risk of bias) 3. Loss of clusters; none of the clusters were lost (low risk of bias) 4. Incorrect analysis; the analyses were correctly conducted and reported (low risk of bias)