Methods	Cluster randomised controlled trial
Participants	13,498 nested in 35 middle schools No data on gender; ≈70% White
Location	Oregon, US.
Interventions	School‐Wide Positive Behavioural Interventions and Supports (SWPBIS) refers to a programme that targets a systemic change process in a whole school or in a district. SWPBIS aims to reduce students’ behaviour problems by changing staff behaviours and developing systems and supports to meet children's behavioural needs.
Programme Deliverer	School staff, teachers and administrators
Evaluator role	Independent
Outcomes	In‐school suspension, out‐of‐school suspension and expulsion School level achievements Antisocial behaviour and aggression Safety Substance use Relationship with teacher Attachment to school rules
Length	One year
Assessment	Baseline, post treatment and 12‐month follow‐up
Attrition	Unclear
COI statement	Not declared
CoFI	Unlikely