RESUMO
CONTEXT: Scales to assess the fatigue in patients with cancer may help the clinical decision-making process. OBJECTIVES: The objective of this study was to cross-culturally adapt and determine the validity of the Brazilian version of Cancer Fatigue Scale. METHODS: Translation and cross-cultural adaptation followed the recommendations of international guidelines. One hundred fifty-one women with breast cancer participated in the validity phase and they filled out the Brazilian version of another instruments (Piper Fatigue Scale Revised, Beck Depression Inventory, Verbal Numerical Rating Scale, and Karnofsky Performance Scale). The measurement properties of reliability, internal consistency, and validity were measured. RESULTS: The few discrepancies identified in the back-translation were solved by consensus, and the Cancer Fatigue Scale was successfully translated and cross-culturally adapted. The Brazilian version of Cancer Fatigue Scale showed good stability (test-retest reliability intraclass correlation coefficient = 0.95, 95% CI = 0.94-0.97 and interexaminer reliability intraclass correlation coefficient = 0.98, 95% CI = 0.97-0.99) and good internal consistency (Cronbach's alpha >0.70 for the three subscales/domains). The high correlation was found with Piper Fatigue Scale (r = 0.643) and Beck Depression Inventory (r = 0.509) in terms of validity. However, a reasonable correlation was found with Verbal Numerical Rating Scale (r = 0.302) and Karnofsky Performance Scale (r = -0.324). CONCLUSION: Here, we validated the Cancer Fatigue Scale in breast cancer Brazilian women meaning its use for the identification and evaluation of cancer-related fatigue in patients with breast cancer.
