Intervention groups
We analysed recordings from 33 of the 42 groups, analysing 90 of the 99 sessions. Reasons for missing data included technical issues and facilitators forgetting to switch on recorders. Interrater reliability was 80% for adherence scores and 90% for competence scores.The overall adherence score was 83% (IQR 67 to 100%) with several components achieving 100%. The two components achieving the lowest scores were The overall competence score was 70% (IQR 50 to 90%) but varied across components of the intervention. The highest competence score was for delivering ‘CHESS intervention Fidelity; Adherence and competence scores