Evaluation of the EORTC QLQ-C30 questionnaire: a comparison with SF-36 Health Survey in a cohort of Italian long-survival cancer patients

Abstract

Background: Despite the large amount of data available about the EORTC QLQ-C30 questionnaire, there have been very few studies focussed on long-survival cancer patients, and no data are available on its performance in the Italian setting.

Patients and methods: Within the framework of a project aimed at evaluating the characteristics of available HR-QOL questionnaires in the Italian language, the EORTC QLQ-C30 questionnaire together with the Short Form 36-item Health Survey (SF-36) were mail-administered to a sample of patients previously recruited in two large multicenter randomized clinical trials on early breast and colon cancers. The properties of the questionnaire were evaluated using standard psychometric techniques and correlation analyses with demographic and clinical independent variables.

Results: In the sample of patients who sent back the questionnaires under evaluation, the EORTC QLQ-C30 showed satisfactory acceptability (response rate = 64% and very low prevalence of missing at item and scale level), and the psychometric analyses confirmed the multi-dimensional conceptualisation in terms of convergent and discriminant validity. Moreover, EORTC QLQ-C30 scales showed substantial correlation with the homologous SF-36 scales. Few socio-demographic (age, gender, schooling) and clinical (type of cancer disease) variables were associated with HR-QOL. Breast cancer patients reported, on average, worse physical health-related scores, but after adjustment for age and education, most of the differences disappeared.

Conclusions: These findings confirm the validity and robustness of the EORTC QLQ-C30 in this sample of long-survival Italian cancer patients. Further ad hoc validation studies are required to evaluate its significance in these particular patients.