Purpose
Fatigue is a prevalent, distressing side effect of cancer and cancer treatment which commonly co-exists with insomnia. Cognitive behavioral therapy for insomnia (CBT-I) has been shown to improve insomnia in cancer patients, but less is known about its ability to impact fatigue. This work is the analysis for a secondary aim of a 4-arm RCT study assessing the combined and comparative effect of CBT-I and a wakefulness-promoting agent, armodafinil (A), to improve sleep and daytime functioning in cancer survivors. Herein, we examine the effect of CBT-I, with and without A, on fatigue in cancer survivors.
Patients and Methods
This study was a four arm factorial study with CBTI-I (Yes/No) versus A (Yes/No). It consisted of 96 cancer survivors (Average age 56 years; 88% female; 68% breast cancer). Fatigue was assessed by the Brief Fatigue Inventory (BFI) and the FACIT-Fatigue scale. The analysis assessed the additive effects of CBT-I and A, and possible non-additive effects where the effect of CBT-I changes depending on the presence or absence of A.
Results
Analyses adjusting for baseline differences showed that CBT-I improved fatigue as measured by two separate scales (BFI: P=0.002, Std. Error=0.32, effect size (ES)=0.46; FACIT-Fatigue: P<0.001, Std. Error=1.74, ES=0.64). Armodafinil alone did not show a statistically significant effect on fatigue levels (all Ps>0.40), nor did the drug influence the efficacy of CBT-I. Structural equation analysis revealed that reductions in insomnia severity were directly responsible for improving cancer-related fatigue.
Conclusions
CBT-I with and without armodafinil resulted in a clinically and statistically significant reduction of subjective daytime fatigue in cancer survivors with chronic insomnia. Armodafinil did not improve CRF and did not change the efficacy of CBT-I. Patients reporting CRF should be screened and, if indicated, treated for insomnia as part of a comprehensive fatigue management program.