Examination of validity of the subjective fatigue scale for young adults

OBJECTIVE: The purpose of this study was to examine the validity of a new type of Subjective Fatigue Scale for young adults (SFS-Y). METHODS: The SFS-Y consisted of 24 item questions representing 6 sub-scales of difficulty of concentrated thinking, languor, reduced activation, reduced motivation, drowsiness and feeling of physical disintegration. The SFS-Y, subjective symptoms index (SSI), chronic fatigue symptoms index (CFSI), multidimensional fatigue index (MFI) and the Chalder fatigue scale (CFS) were administered to 5435 students aged 15-20 yr. RESULTS: It was inferred that SFS-Y can evaluate individual differences from the viewpoints of score distribution and discrimination power. It was considered that the SFS-Y has high generality because it includes many question items with a similar content to existing fatigue scales and it can do multiple evaluations covering almost all aspects of existing scales. The relationships between sub-scales in the SFS-Y and existing fatigue scales were high in sub-scales with similar names and was low in ones with different names. CONCLUSION: The Subjective Fatigue Scale developed to evaluate subjective fatigue for youths was considered to be excellent in validity and to be effective scale.