[Questionnaire on the Experience of the Art Therapy Group in Psychosomatics from Patient View (FEKTP) - Construction and Validation of a Measuring Instrument].

Art therapy is a clinically accepted method of therapy, but there are still very few studies that deal with the efficacy, change factors or mode of action of art therapy. In particular, there is a dearth of research instruments and psychometrically verified research tools specially fitted for art therapy which measures the experience dimensions of the art therapy group from the patient's point of view. Hence, it provides evidence of its effectiveness, better understands the art therapy group processes and serves quality assurance. The aim of the present study was to develop and validate the questionnaire on the experience of the art therapy group from patient view (FEKTP). This questionnaire is based on Grawe's and Yalom's conceptions of change factors in group therapy. 133 patients participated in the study and completed the FEKTP directly after the 6th art therapy session. Patients additionally received established questionnaires concerning clinical symptoms and experience processes at the beginning and end of treatment. Factor analysis demonstrated a clear factor structure of the FEKTP, which corresponded to the theoretically predicted subscales to the greatest extent. The test psychometric main quality criteria of the FEKTP (reliability, validity and objectivity) can be classified as acceptable to good range. The criterion validity appear to be given, but should be examined more exactly in future studies. Thus, a valid instrument for the systemic detection of general change factors for art therapy is now available. The questionnaire can be recommended for research as well as clinical contexts.