Reliability and validity of the functional assessment of cancer therapy-breast quality-of-life instrument

Purpose: This is the first published report on the validation of the Functional Assessment of Cancer Therapy-Breast (FACT-B), a 44-item self-report instrument designed to measure multidimensional quality of life (QL) in patients with breast cancer. The FACT-B consists of the FACT-General (FACT-G) plus the Breast Cancer Subscale (BCS), which complements the general scale with items specific to QL in breast cancer. The FACT-B was developed with an emphasis on patients' values and brevity and is available in nine languages. Methods and Results: Two validation samples were used for this report. The first (n = 47) was tested twice over a 2-month period to assess sensitivity to change, Significant sensitivity to change in performance status rating (PSR) was demonstrated for the FACT-B total score, the Physical Well-Being (PWB) subscale, the Functional Well-Being (FWB) subscale, and the BCS. Sensitivity to change in QL as measured by the Functional Living Index-Cancer (FLIC) was documented in the FACT-B total score, PWB, FWB, and Emotional Well-Being (EWB). Additional validity and reliability data were obtained from a larger sample (n = 295). The alpha coefficient (internal consistency) for the FACT-B total score was high (alpha = .90), with subscale alpha coefficients ranging from .63 to .86. Evidence supported test-retest reliability, as well as convergent, divergent, and known groups validity. Conclusion: The FACT-B is appropriate for use in oncology clinical trials, as well as in clinical practice. It demonstrates ease of administration, brevity, reliability, validity, and sensitivity to change. (C) 1997 by American Society of Clinical Oncology.