Sensitivity to change of the EORTC quality of life module measuring cancer-related fatigue (EORTC QlQ-Fa12): Results from the international psychometric validation

Objective The European Organisation for Research and Treatment of Cancer Quality of Life Group (EORTC QLG) has developed a multidimensional instrument measuring cancer-related fatigue, the EORTC QLQ-FA12. The analysis of sensitivity to change is an essential part of psychometric validation. With this study, we investigated the EORTC QLQ-FA12's sensitivity to change. Methods The methodology follows the EORTC guidelines of EORTC QLG for phase IV validation of modules. We included cancer patients undergoing curative and palliative treatment at t1 and followed them up prospectively over the course of their treatment (t2) and 4 weeks after completion of treatment (t3). Data were collected prospectively at 17 sites in 11 countries. Sensitivity to change was investigated using analysis of variance. Results A total sample of 533 patients was enrolled with various tumour types, different stages of cancer, and receiving either curative treatment (n=311) or palliative treatment (n=222). Over time all fatigue scores were significantly higher in the palliative treatment group compared with the curative group (p <.001). Physical fatigue increased with medium effect size over the course of treatment in the curative group (standardized response mean [SRM] (t1,t2) = 0.44]. After treatment physical [SRM (t2,t3) = 0.39], emotional [SRM (t2,t3)= 0.28] and cognitive fatigue (SRM [t2,t3] = 0.22) declined significantly in the curative group. In the palliative group, emotional (SRM [t2,t3] = 0.18) as well as cognitive [SRM [t2,t3] = 0.26) fatigue increases significantly. Conclusions The EORTC-QLQ-FA12 proved to identify clinically significant changes in fatigue in the course of curative and palliative cancer treatment.