Evaluation of the "Consultation and Relational Empathy" (CARE) measure by means of Rasch-analysis at the example of cancer patients.

Objective: The aims of this study are: (1) analysis of unidimensionality of the German version of the "Consultation and Relational Empathy" (CARE) measure and (2) identification of moderating variables affecting the scale structure.

Methods: The CARE-measure was evaluated by means of Rasch-analysis in a sample of N=326 cancer patients. Association of diagnosis and treatment as well as patients' characteristics was analyzed by person-fit measures and Differential Item Functioning.

Results: Nine of the original 10 CARE items fit to the Rasch-model. For breast and prostate cancer, as well as for patients taking complementary and alternative medicine treatment, item biases affect the scale structure. Furthermore, older patients and patients with higher social support exhibit substantial deviations from model predictions.

Conclusions: Only the nine-item version of the CARE-measure allows for the unidimensional assessment of physician empathy. Especially for specific diagnosis and treatment groups, the CARE-items indicate variations in the underlying latent construct of physician empathy.

Practice Implications: The CARER-measure provides a theory-based and psychometrically sound basis for the assessment of PE. It can be used to enhance the fairness of the assessment and to further identify valuable information about the influence of patient characteristics on the structure of the construct PE.