A quick assessment of reliable change in fatigue: Reliable change indices of the modified fatigue impact scale - 5 item (MFIS-5).

Abstract Background Reliably monitoring changes in fatigue is an ongoing concern. Objective Evaluate reliable change using the Modified Fatigue Impact Scale 5-item version (MFIS-5) in people with MS (PwMS). Methods The MFIS-5 was administered at three time points in 157 PwMS. Test-retest reliability and reliable change scores were calculated at the 0.70, 0.80, 0.90, and 0.95 confidence intervals. Results Difference scores of 3, 4, 5, and 6 represent statistically meaningful change at the 0.70, 0.80, 0.90, and 0.95 confidence intervals, respectively. Conclusion Cut points derived from this study and prior work can help reliably assess changes in fatigue over time.