An international field study for the reliability and validity of the EORTC communication questionnaire EORTC QLQ-COMU26.

Background: The EORTC Quality of Life Group has developed a questionnaire to evaluate cancer patients' perception of their communication with healthcare professionals (HCPs): the EORTC QLQ-COMU26. In this study we test the validity and reliability of this novel measure in an international and culturally diverse sample of cancer patients.

Methods: Cancer patients completed the following EORTC questionnaires at two time points (before and during treatment): the QLQ-COMU26 (including a debriefing questionnaire), the QLQ-C30, and specific IN-PATSAT32 scales. These data were used to assess: the cross-cultural applicability, acceptability, scale structure, reliability, convergent/divergent validity, known-groups validity, and responsiveness to change of the QLQ-COMU26.

Results: Data were collected from 498 patients with various cancer diagnoses in 10 European countries, Japan, Jordan and India (overall 5 cultural regions). At most, only 3% of patients identified an item as confusing and 0.6% as upsetting, which indicates that the questionnaire was clear and did not trigger negative emotional responses. Confirmatory factor analysis and multi-trait scaling confirmed the hypothesised QLQ-COMU26 scale structure comprising six multi-item scales and four single items (RMSEA = 0.025). Reliability was good for all scales (internal consistency > 0.70; test-retest reliability > 0.85). Convergent validity was supported by correlations of ≥ 0.50 with related scales of the IN-PATSAT32 and correlations < 0.30 with unrelated QLQ-C30 scales. Known-groups validity was shown according to sex, education, levels of anxiety and depression, satisfaction with communication, disease stage and treatment intention, professional evaluated, and having a companion during the visit. The QLQ-COMU26 captured changes over time in groups that were defined based on changes in the item of satisfaction with communication.

Conclusion: The EORTC QLQ-COMU26 is a reliable and valid measure of patients' perceptions of their communication with HCPs. The EORTC QLQ-COMU26 can be used in daily clinical practice and research and in various cancer patient groups from different cultures. This questionnaire can help to improve communication between patients and healthcare professionals.