Psychometric and clinical assessment of the 13-item reduced version of the fatigue scale-adolescent instrument

Fatigue is one of the most common and distressing symptoms experienced by adolescents during and after treatment for cancer. The lack of reliable and valid instruments has prevented an accurate assessment of the trajectory of fatigue among adolescent oncology patients. The purposes of this study were to identify the items on the Fatigue Scale-Adolescent (FS-A) that distinguished adolescents with high fatigue and to identify the most sensitive and specific score ("cut score") in order to identify those in need of a fatigue intervention. Rasch methods were used to identify FS-A items that distinguished adolescents with high cancer-related fatigue, and results indicated that the 14-item FS-A could be reduced to 13 items. The 13-item FS-A was assessed for its psychometric properties, with application of the receiver operating characteristics curve analysis to the responses from 75 adolescents. The internal consistency coefficient was .87, and a 4-factor confirmatory analysis achieved good fit coefficients. The identified cut score was 31, with 66.6% sensitivity and 82.6% specificity; 16 (21.33%) of the patients scored 31 or higher. The 13-item FS-A has acceptable psychometric properties and is able to identify adolescent oncology patients with high fatigue.