There has been increased research interest into the concept of treatment integrity within psychotherapy research. The Competence and Adherence Scale for Cognitive Behavioural Therapy (CAS-CBT) was developed to measure therapists’ competence and adherence in cognitive behavioural therapy (CBT), when delivered to children and youth with anxiety disorders.

The aim of this study was to evaluate the psychometric properties of the CAS-CBT in a naturalistic treatment setting.

Ratings of 212 randomly selected sessions from a clinical effectiveness trial for children with anxiety disorders (n = 165, mean age = 10.46 years, SD = 1.49) were analysed to assess the psychometric properties of CAS-CBT. Therapy format included both individual sessions and group sessions.

Internal consistency for the CAS-CBT was excellent (Cronbach’s alpha = .88). Factor analysis suggested a two-factor solution for the total sample, where the first factor was related to CBT structure and session goals, and the second factor was associated with process and relational skills. The individual CBT treatment condition (ICBT) and group CBT treatment condition (GCBT) showed the same factor solution.

The CAS-CBT is a feasible and reliable measure for assessing competence and adherence to CBT in the treatment of anxious children. Future research is needed to further assess the generalizability of this scale, its psychometric properties in different treatment populations and with other treatment approaches, and ideally with larger sample sizes.