An international validation study of the EORTC QLQ-INFO25 questionnaire: an instrument to assess the information given to cancer patients.

AIM: The EORTC Quality of Life (QOL) Group has developed an instrument to evaluate the information received by cancer patients. This study assessed the psychometric characteristics of the EORTC INFO module in a large international/multi-cultural sample of cancer patients.
METHODS: The provisional 26-item information module (EORTC INFO26) was administered with the EORTC QLQ-C30 and the information scales of the inpatient satisfaction module EORTC IN-PATSAT32 on two occasions during the patients' treatment and follow-up period. Questionnaire-hypothesised scale structure, reliability, validity and responsiveness to changes were evaluated through standard psychometric analyses. Patient acceptability was assessed with a debriefing questionnaire.
RESULTS: The study comprised 509 patients from 8 countries (7 European countries and Taiwan) with different cancers and disease stages. Multi-trait scaling analysis led to the deletion of one item but confirmed the hypothesised 4 multi-item scales (information about disease, medical tests, treatment and other services) and eight single items. Internal consistency for all scales was good (α>0.70), as was test-retest reliability (intraclass correlations>0.70). All items can be combined to generate a single score (α>0.90). Convergent validity was supported by significant correlations with related areas of IN-PATSAT32 (r>0.40). Low correlations with EORTC QLQ-C30 scales confirmed divergent validity (r<0.30) The EORTC INFO-25 module discriminated among groups based on gender, age, education, levels of anxiety and depression, information wishes and satisfaction. Only one scale captured changes over time.
CONCLUSIONS: The EORTC QLQ-INFO 25 is a reliable and valid self-reported instrument. The module can be used in cross-cultural observational and intervention studies.