The consultation and relational empathy measure: an investigation of its scaling structure

Purpose: The Consultation and Relational Empathy (CARE) measure is recommended to evaluate the quality of care. However, there is no evidence that it is valid in rehabilitation. Aims were to examine the internal construct (factorial) validity of the CARE in the assessment of the patient-therapist relationship. Method: CARE data were part of an experimental study of acupuncture and different currently used acupuncture placebo controls, including 213 patients (age 66.8, SD 8.3, 58% female) with chronic stable hip or knee pain of mechanical origin, waiting for a joint replacement. CARE was completed two weeks into the study and on completion, two weeks later. Data analysis: Cronbach alpha, factor analysis and Rasch analysis. Results: Internal construct validity was supported (82% of variance explained by the first factor; fit to the Rasch model chi(2) = 18.2, P = 0.57). CARE was unidimensional, had local independence of items, good item fit, absence of Differential Item Functioning and invariance over time. Three percent of people did not complete items 9 & 10. Conclusions: CARE satisfied strict criteria for internal construct validity. An interval scale transformation is available that can be used in clinical practice and research. Further work is required to investigate item non-response and how this may be dealt with in clinical settings.