Introduction: Fighter pilots are a population particularly vulnerable to developing mental fatigue, which puts the safety of military operations at risk. Although there is no gold standard tool for its assessment, Yoshitake's Feeling of Fatigue Scale (FFS) appears promising for application to fighter pilots as it has already been validated for Brazilian commercial airline pilots. The objective of this study was to evaluate the psychometric properties of the FFS in Brazilian fighter pilots.
Methods: This was a cross-sectional study, carried out between March-August 2023, with 58 fighter pilots operating F-5M and JAS 39E aircraft. A sociodemographic questionnaire, the FFS, and the Samn-Perelli Scale were applied in two moments with a maximum interval of 7 d between them. The reliability/reproducibility and agreement of the instrument were evaluated using Cronbach's α, Cohen's κ test (for categorical variables), and the intraclass correlation coefficient for numerical variables in the test-retest. Criterion validation was carried out using the Samn-Perelli Scale. Data were also analyzed using Statistical Package for Social Sciences statistical software, version 25.0.
Results: The instrument presents good reliability, being suitable for evaluating the domains of drowsiness [a = 0.840, F = 6.241, confidence interval (CI): 0.576-0.827], concentration (a = 0.907, F = 10.739, CI: 0.726-0.894) and physical discomfort (a = 0.747, F = 3.948, CI: 0.385-0.730). The criterion validity analysis showed that the FFS is valid and accurate for assessing mental fatigue in Brazilian fighter pilots.
Discussion: The psychometric properties of the FFS are suitable for assessing mental fatigue in this population. Milioli Ferreira D, Morisco de Sá P, Bittencourt Ferreira D. The Feeling of Fatigue Scale for Brazilian fighter pilots. Aerosp Med Hum Perform. 2025; 96(1):39-44.
Keywords: mental fatigue; military; pilot; test reproducibility; validation study.