Measurement of the quality of life during different clinical phases of breast cancer.

This cross-sectional study was designed to evaluate the self-rated quality of life of Taiwanese breast cancer patients at the time of diagnosis and during various phases of treatment. A total of 115 patients at different clinical stages of breast cancer completed the study. The questionnaires consisted of the Medical Outcome Survey 36-Item Short Form Health Surveys (SF-36), the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire--Cancer 30 (EORTC QLQ-C30), and questions measuring utility using visual analog scale (VAS), standard gamble (SG), and time trade-off (TTO) methods. The patients filled out the questionnaires, with interviewers' assistance as requested. Cronbach's alpha coefficients of internal consistency for the SF-36, based on the US factor structure, were 0.84 for raw scores and 0.87 and 0.88 for the physical and mental components, respectively. Cronbach's alpha for the EORTC QLQ-C30 was 0.86. The correlations between items in the SF-36 and the EORTC QLQ-C30 that examined similar dimensions were high. Significant differences were found in most dimensions of quality of life across different clinical stages. The three utility scores, however, showed no significant differences among patients in different clinical stages. Patients in the chemotherapy and recurrence phases usually had the lowest quality of life scores, while those in the follow-up phase had the highest. The results of this study demonstrate the applicability of quality of life measurements in helping health professionals identify the physical, mental, and social problems of breast cancer patients in different phases of the clinical process.