Moderators and long-term effectiveness of cognitive behaviour therapy for fatigue during cancer treatment

Objective A randomised controlled trial (RCT) demonstrated that cognitive behaviour therapy (CBT) for fatigue during curative cancer treatment was effective shortly after cancer treatment. This study aimed to identify which patient characteristics predict fatigue improvement after CBT. In addition, the long‐term effectiveness was investigated. Methods Patients with various malignancies participated in the RCT (n = 210). Participants were assessed before cancer treatment (T1), postintervention (T2), which was at least 2 months after cancer treatment, and after 1‐year follow‐up (T3). Monthly fatigue assessments were completed between T2 and T3. A regression analysis with interactions was performed to determine if domains of quality of life (EORTC‐QLQ‐C30) functioning (Health Survey Short Form‐36) or psychological distress (Symptom Checklist‐90) moderated the effect of CBT on fatigue. Analyses of covariance were used to study the long‐term effectiveness of CBT. Results Fatigue at T2 was predicted by a significant interaction between self‐reported cognitive functioning and CBT. No interactions were found between other domains of quality of life, functioning, psychological distress and CBT. At T3, no significant difference on fatigue was found between CBT and usual care. Exploratory analyses showed that the difference nearly reached significance until 7 months postintervention. Conclusions Patients who experienced more concentration and memory problems at T1 benefited more from CBT for fatigue and are indicators. After a year of follow‐up, the effect of CBT for fatigue was no longer observed, and the effect on fatigue seemed to be diminished 7 months postintervention. The implication is that CBT for fatigue should be offered to patients with cancer with the highest chance to benefit. Copyright © 2011 John Wiley & Sons, Ltd.