[Change Factors in Group Therapy: Development and Validation of a Questionnaire]

While the efficacy of group therapy is sufficiently confirmed, there is a research gap concerning relevant therapeutic processes. Particularly, there is a dearth of integrative instruments that assess a broad spectrum of group therapeutic change factors. Hence, the aim of the current investigation was the validation of the newly developed "Scale for the assessment of therapeutic processes in group therapy (FEPiG)" based on Grawe's general psychotherapy and Yalom's conception of change factors in group therapy. 303 Patients (110 outpatients, 193 inpatients) participated in the study and completed the FEPiG as well as established measures concerning group processes. The outpatients additionally received established questionnaires concerning clinical symptomatology and filled out all instruments at the beginning and end of treatment. Factor analysis demonstrated an excellent factor structure of the FEPiG, which corresponded to the theoretically predicted subscales. Internal consistencies of the FEPiG were good to excellent and correlated with established process measures, which indicated convergent validity. While the FEPiG change factors subscales at the beginning of therapy were not correlated with outcome, associations between increases in change factors across the course of therapy and symptom reduction could be demonstrated.