Quality of life among brazilian women having undergone surgery for breast cancer: validity and reliability of the quality of life questionnaire (EORTC QLQ-C30) and breast cancer module (QLQ BR-23).

Abstract

The aim of the present study was to verify the measurement properties of the generic Quality of Life Questionnaire (EORTC QLQ-C30) and specific Breast Cancer Module (QLQ BR-23) for assessing the quality of life of Brazilian women having undergone breast cancer surgery. The measurement properties of the instruments were evaluated with regard to internal consistency, discriminant validity, criteria validity, and test-retest reliability. Adequate internal consistency indices (α=0.47 to 085) were demonstrated. Stepwise multiple linear regression analysis was used to determine criteria validity, demonstrating that the domains for pain (PA), emotional functioning (EF) and social functioning (SF) explained 46% of the variance. The instruments presented satisfactory test retest reliability in both the interobserver and intra-observer evaluations. The EORTC QLQ-C30 and BR-23 instruments proved adequate in assessing the quality of life of Brazilian women having undergone breast cancer surgery and also demonstrated the importance of assessing the quality of life as a health indicator with the aim of seeking more qualified and humanized care.