Adaptive Compared With Persistent Fatigue in Allogeneic Hematopoietic Cell Transplantation Survivors

BACKGROUND: Clearly demarcating the differences between adaptive fatigue, a normal physiological phenomenon, and persistent fatigue, a symptom that requires treatment, is vital for phenotypic characterization in allogeneic hematopoietic cell transplantation (alloHCT) survivors. OBJECTIVE: This study compared the phenotypic characteristics (symptoms and behavioral manifestations) of alloHCT survivors with adaptive versus persistent fatigue using 2 approaches to categorize fatigue. METHODS: This 2-group, comparative study examined differences in sleep, emotional distress, cognitive functioning, and pain in 38 alloHCT survivors with adaptive compared with persistent fatigue using 2 approaches to classify fatigue (Fatigue Severity Scale cut scores and responses to standard clinical questions regarding occurrence, duration, and resolution of fatigue with rest). RESULTS: = 17, 45%). AlloHCT survivors with persistent fatigue reported significantly greater emotional distress and reduced cognitive abilities compared to those with adaptive fatigue when using the Fatigue Severity Scale. No significant differences were found between the 2 groups using standard clinical questions. CONCLUSIONS: Persistent fatigue is empirically different from adaptive fatigue. The phenotypic characteristics differed depending on the classification method (cut scores on the Fatigue Severity Score or responses to standard clinical questions). Understanding how methods to classify fatigue influenced the results is important to avoid under- or overtreatment of persistent fatigue and the co-occurring symptoms and behavioral manifestations. Recognizing and identifying therapeutic targets for persistent fatigue is essential for delivering comprehensive survivorship care in alloHCT survivors.