Nammontri 2013

Methods	Study design: cluster‐randomised trial Conducted in: Khonkaen, Thailand Unit of randomisation: schools Unit of analysis: individual Setting: schools Funded by: "This study was funded by the Royal Thai Government Ministry of Public Health,Thailand" Duration of the study: 3 months
Participants	Inclusion criteria: Schools were eligible to participate if they were in a suburban area in Khonkaen, had 200 to 300 students, including 20 to 30 grade 5 students 10 to 12 years of age Exclusion criteria: not reported Age at baseline: 10 to 12 years N (control baseline): 6 schools, 128 children N (control post intervention): 6 schools, 127 children N (control follow‐up): 6 schools, 125 children N (intervention baseline): 6 schools, 133 children N (intervention post intervention): 6 schools, 133 children N (intervention follow‐up): 6 schools, 132 children Recruitment: 12 schools were selected randomly to participate in the study. Schools were allocated to the 2 groups: control and intervention according to the sequence. Six schools formed an intervention group, and 6 a control group Gender: not reported
Interventions	Interventions Oral health education delivered as seven 40 to 60‐minute sessions over 2 months. The focus was on child participation and empowerment. The first 4 sessions consisted of didactic instructions, discussion, activities and games Whole school participatory approach: The last 3 sessions were brainstorming, evaluation and planning, and involved the whole Control: no intervention Duration of intervention: 2 months
Outcomes	Gingival health DMFT
Implementation related factors	Theoretical basis: sense of coherence Resources for implementation: not reported Who delivered the intervention: trained teachers PROGRESS categories assessed at baseline: parent’s occupation, family income and age PROGRESS categories analysed at outcome: not reported Outcomes related to harms/unintended effects: not reported Intervention included strategies to address diversity or disadvantage: not reported Economic evaluation: not reported
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random sequence of blocks was used to generate the allocation sequence for schools
Allocation concealment (selection bias)	Low risk	All clusters were randomised at the same time
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only 1 participant was lost to follow‐up
Selective reporting (reporting bias)	Unclear risk	Unclear
Other bias	Unclear risk	Unclear
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Unclear
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Unclear