Development of the Hirai Cancer Fatigue Scale: Testing its reliability and validity.

Purpose: The purpose of this study was to develop the Hirai Cancer Fatigue Scale (HCFS) to assess the fatigue experienced by cancer patients, and to verify its reliability and validity.

Methods: Based on qualitative research about the perception of fatigue by Japanese cancer patients, we developed a questionnaire. The content validity was confirmed by 5 expert oncology nurses and 5 oncologists. 281 Japanese cancer patients participated in this study. Construct validity was analyzed using factor analysis, and internal consistency was analyzed using Cronbach's α coefficient.

Results: A 15-item scale with 3 dimensions, "physical/mental sensation", "activity-related sensation" and "cognitive sensation," was developed by factor analysis. This scale had an overall Cronbach's α coefficient of .943 and a test-retest reliability coefficient of r = .820 (p < 0.01), confirming the high reliability of the scale. The correlation coefficient was r = .759 (p < 0.01) between HCFS and abridged Profile of Mood States-Fatigue (POMS-F), and r = .763 (p < 0.01) between HCFS and Cancer Fatigue Scale (CFS), both showing high correlations and confirming criterion-related validity.

Conclusion: HCFS enables reliable and valid evaluation of Japanese cancer patients' fatigue. Use of the HCFS would assist in convenient self-evaluation of fatigue, and would allow information to be effectively provided to healthcare professionals. It could also be used for outcome evaluation in an intervention study.