[A group therapy assessment tool (GrETha-Q)].

Area of Science:

• Psychology
• Psychotherapy Research
• Clinical Psychology

Background:

• Group therapy is a widely used therapeutic modality.
• Assessing treatment efficacy and subjective patient experience is crucial for treatment improvement.
• Existing instruments may not fully capture the nuances of group therapy outcomes.

Purpose of the Study:

• To develop and validate a questionnaire for assessing nonspecific treatment efficacy and subjective perceived efficacy in group therapy.
• To provide a reliable and valid tool for researchers and clinicians evaluating group therapy outcomes.

Main Methods:

• Development of a preliminary questionnaire.
• Administration to 151 subjects undergoing group therapy.
• Psychometric evaluation using the Rasch model.

Main Results:

• The questionnaire demonstrated a good score range, high reproducibility, and adequate internal consistency.
• Item difficulty hierarchy remained stable across demographic groups (sex, age, professional level).
• The Rasch model confirmed the psychometric soundness of the instrument.

Conclusions:

• The developed questionnaire is a psychometrically sound instrument for measuring group therapy efficacy.
• The tool can reliably assess both objective treatment effects and subjective patient perceptions.
• Findings support the use of this questionnaire in clinical practice and research for evaluating group therapy effectiveness.