Development of a Reference Chart for Monitoring Cancer-Related Fatigue Throughout a Supervised Exercise Program

Background: Cancer-related fatigue (CRF) is one of the most reported and functionally limiting symptoms experienced by individuals living with and beyond cancer. Exercise is effective at reducing CRF, although currently it is not possible to predict the magnitude and time course of improvement for an individual participating in an exercise program. Objective: To develop a reference chart of CRF improvement for individuals participating in a 3-month cancer-specific exercise program. Methods: In this retrospective cohort study, CRF was assessed every 2 weeks (using the FACIT-Fatigue scale, range: 0-52, with lower scores indicating greater fatigue) in 173 individuals participating in a 3-month supervised exercise program (741 observations). No cancer types were excluded and individuals were either undergoing chemotherapy and/or radiation, or within 6 months of completing treatment. The reference chart was developed using Generalized Additive Models for Location Scale and Shape. Results: Each participant had an average of 4 CRF observations. Lower centiles demonstrated greater improvement than higher centiles (11 points over the duration of the program for the 10th and 4 points for the 90th percentiles). Limitations: The population is biased to individuals self-selecting or being referred to a clinical exercise program. Conclusions: This reference chart provides a novel method of monitoring CRF improvement during a cancer-specific exercise program. Setting appropriate expectations and informing exercise prescription adaptation are discussed in the context of representative data from 3 participants. Future research can investigate improvements in clinical outcomes and the remote monitoring of CRF through the implementation of the reference chart.