Development and preliminary validation of the Group Cognitive Therapy Scale.

Aim: The aim of this research was to create a scale to assess the competency of therapists who conduct group cognitive behavioral therapy (G-CBT). The scale is intended to serve as a tool to aid the training of therapists.

Methods: Three stepped studies were conducted. Process 1: Through literature review and experts' consensus process, essential skills for G-CBT were articulated and categorized according to the criteria of the Cognitive Therapy Scale, a well-established rating scale for evaluating clinicians' skills in individual cognitive behavioral therapy. The list of those skills was organized into a rating scale. Process 2: Behavioral anchors were added to each skill and were classified by the levels of difficulty (beginner, intermediate, and advanced levels), based on the rating by G-CBT experts. Process 3: Inter-rater reliability and validity of the rating scale were examined in a sample of 41 videotaped G-CBT sessions of actual clinical sessions and educational role-plays.

Results: The 12-item Group Cognitive Therapy Scale (G-CTS) was developed. It consists of 11 items that are adapted from the original Cognitive Therapy Scale, and a new 12th item called "Intervention using relationships with other participants," which describes therapists' skills to address group dynamics. The G-CTS showed excellent internal consistency (Cronbach's : 0.95), satisfactory inter-rater reliability (interclass correlation coefficients: 0.65-0.88), and high predictive validity.

Conclusion: A novel rating scale to evaluate therapists' competency in G-CBT was developed and successfully validated. The G-CTS behavioral checklist created in this study provides concrete guidelines that can be used by therapists to hone their skills in G-CBT.