What are the best terms in Portuguese to explain the concepts of fatigue and depression in cancer patients?

Objective: Although fatigue and depression are well-accepted clinical terms in the English language, they are ill defined in many other languages, including Portuguese. We aimed to investigate the most appropriate words to describe cancer-related fatigue (CRF) and depression in Brazilian cancer patients. Method: The interviewers read to patients two clinical vignettes describing fatigued patients and two others describing depressed patients. Participants were asked to choose from among fatigue, tiredness, weakness, depression, and sadness the best and worst terms to explain the vignettes. In addition, they were administered an instrument containing numeric rating scales (NRSs), addressing common symptoms, including the aforementioned terms. Pearson correlation analysis and accuracy diagnostic tests were conducted using the Hospital Anxiety and Depression Scale (HADS) and the Functional Assessment of Cancer Treatment-Fatigue (FACIT-F) as references. Results: Among the 80 participants, 40% reported that the best term to explain the concept of CRF was tiredness, and 59% chose sadness as the best descriptor of depression. Regarding diagnostic accuracy, the areas under the curve (AUCs) for fatigue, weakness, and tiredness were 0.71, 0.81, and 0.76, respectively; the AUCs for depression and sadness ranged from 0.81 to 0.91 and 0.73 to 0.83, respectively. Negative correlations were found among FACIT-F fatigue subscale scores and NRS scores for fatigue (r = -0.58), tiredness (r = -0.67), and weakness (r = -0.62). Regarding depression, there were positive correlations between HADS-D scores and both NRS for depression (r = 0.61) and sadness (r = 0.54). Significance of results: Tiredness was considered the best descriptor of CRF. Taking into consideration the clinical correlation with depression scores, the term depression was accepted as the best term to explain the concept of depression.