To develop a psychometrically sound short version of the 13-item Lee Fatigue Scale using a Rasch model application.
A convenience sample of 102 women with HIV/AIDS completed the Lee Fatigue Scale in the morning and evening. The scale was assessed using a Rasch analysis approach. We used a stepwise approach of removing the item with the least goodness-of-fit for internal scale validity in sequential analyses while monitoring unidimensionality and sensitivity to detect levels of fatigue.
The item reduction process terminated with a 5-item version (items 1, 4, 5, 11, and 12 from the original 13-item version). Analyses confirmed that both the original and short-form versions of the Lee Fatigue Scale demonstrated evidence of internal scale validity, unidimensionality, and sensitivity to at least three levels of fatigue (low, moderate, and high severity). Differential test functioning indicated that the original and short-form versions yielded similar ratings for 95 % of respondents.
A 5-item version of the Lee Fatigue Scale has satisfactory measurement properties and met criteria related to unidimensionality and ability to separate levels of fatigue. This version may be useful in studies measuring fatigue repeatedly over relatively short intervals.