Prinz 1994.

Methods	Cluster randomisation using coin toss.
Participants	25 grade 1‐3 classes randomised, 95 students scoring >= 65 on aggressive subscale of CBCL‐TRF , and 101 scoring <=60 on aggressive subscale and >median on communication effectiveness subscale.
Interventions	I: Peer coping skills training (1 x 50 minute session per week for 19‐24 weeks) + Minimal classroom intervention ( a class wide program to promote prosocial behaviour). C: Minimal classroom intervention only
Outcomes	(1) *CBCL‐TRF aggression subscale (unblinded)
Notes	Data collected immediately and at 6 months.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear