Stallard 2012a.

Methods	Design: cluster‐RCT Conducted by the team who developed the intervention: no
Participants	Description: targeted Cut‐point for inclusion for indicated studies: MFQ ≥ 2.0 over 2 assessments approx. 2 weeks apart What risk was basis of inclusion for selected studies: N/A Diagnostic interview to exclude those with current or previous depression: diagnostic interview not used to exclude those with current depression. Those with past episodes of depression not excluded. Baseline severity of depression: SMFQ: 10.6 (subthreshold)   Mean age: not specified Age range: 8 to 11 Percentage male: 34.9% Setting: school   State what psychiatric diagnoses were excluded: none Suicide risk excluded: no Parents with history of schizophrenia/bipolar disorder excluded: no   Country: UK
Interventions	Broad category: CBT with elements of IPT (for further information on intervention components, see Table 3) Manualised: yes Online: no Name of programme: RAP Number of sessions: 9 sessions and 2 booster sessions Length of sessions: 50 to 60 minutes Intensity (total number of hours): up to 9 hours (not including booster sessions) Duration of treatment period: unclear Group size: unclear Delivered by: students with at least an undergraduate degree in a relevant discipline Fidelity: assessed as adequate   Type of comparison: TAU comprising usual personal health and social education classes provided by the school
Outcomes	Diagnosis: SMFQ ≥ 5.0 Name of self‐report depression measure: SMFQ Name of clinical report depression measure: N/A Name of anxiety measure: RCADS Name of general functioning measure: N/A Assessment points: 12 months (medium‐term)
Notes	Author contacted for methodological detail: no Author contacted for treatment manual: no Author contacted for outcome data: no
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"...we allocated year groups on a 1:1:1 ratio. We balanced the trial arms for key characteristics by calculating an imbalance statistic for a large random sample of possible allocation sequences" (no pagination specified).
Allocation concealment (selection bias)	Low risk	"A statistician with no other involvement in the study randomly selected one sequence from a subset..." (no pagination specified)
Blinding (performance bias and detection bias) Subjects	Unclear risk	The nature of the trial suggests it is likely participants could have remained blind to the fact they were allocated to a placebo control group. However, without access to the participant information sheets and PLS, level of blinding cannot be ascertained.
Blinding (performance bias and detection bias) Assessors	Unclear risk	Outcomes self‐reported but there is no detail about blinding. Assessor blinding therefore not applicable.
Incomplete outcome data (attrition bias) All outcomes	High risk	Proportion of participants with incomplete post‐intervention self‐reported depression scores: 21.1% Means and SDs used in meta‐analysis based on what data: observed cases Intention‐to‐treat analyses: multiple imputation
Selective reporting (reporting bias)	Low risk	Trial protocol (i.e. Stallard 2010) would suggest that all intended outcomes were assessed
Other bias	Low risk	Trial not conducted by those who developed the intervention
Implementation integrity	Low risk	Implementation integrity assessed: yes (5% of sessions) Implementation integrity adequate: 89.00% of sessions covered core tasks, with at least 75% of the core tasks covered in the remaining 11% of sessions Implementation integrity reported: yes