Measurement of CRF
The Cancer Fatigue Scale (CFS) was designed by Okuyama and validated by 307 cancer patients19. CFS includes 15 items, with a total score of ≤5 for no fatigue, 6-15 for mild fatigue, 16-30 for moderate fatigue, and 31-60 for severe fatigue. The scale has been used in different cancer patients. It has been verified that the scale is simple and easy to complete, even for patients with advanced cancer.