Evaluation of a fatigue model using data from published napping studies.

The authors have previously published the development and empirical validation of a work-related fatigue model. However, published work has not involved data from napping studies. The aim of this paper is to determine how closely the model predicts changes in subjective and objective measures from data published from napping studies. The regression results between the model outputs and logical reasoning, multiple sleep latency test scores, self-rated alertness, profile of mood state fatigue, visual vigilance and reaction time were all strong to very strong (R2 = 0.4-0.9). Only digit symbol substitution revealed moderate (R2 = 0.1-0.2) regression values. The outputs of the model reflect changes due to naps of varying duration and timing measured at varying periods following a nap. Together with the outputs from previous investigations, these results further support the potential use of the fatigue model in operational settings. This appears to be true in settings that utilise napping as well as those that do not.