0691 A FIELD STUDY OF MARINE PILOTS’ PERFORMANCE, FATIGUE, AND SLEEPINESS LEVELS

Abstract Introduction: Working on atypical schedules leads to sleep-wake disturbances and increased fatigue. This study aims to quantify how time-of-day, work duration, and time awake interact to affect ship pilots’ performance and sleepiness. Methods: A total of 17 male St-Lawrence River ship pilots (46.0 ± 7.2 years; ±SD) participated to a 16–21 day field study comprised of a succession of work and rest days. The sleep-wake cycle was documented by wrist-worn actigraphy and sleep-wake log. Performance was assessed by a 5-min psychomotor vigilance task (PVT) at the start and end of each work and rest day. Sleepiness and fatigue were assessed 5x/day by the Karolinska sleepiness scale (KSS) and the Samn Perelli Fatigue scale, respectively. Probability of presenting increased sleepiness and fatigue as well as reduced performance was modelled using repeated measure logistic regressions. Specifically, the probability of exceeding 1 SD from each individual’s mean was modelled. Results: Ship transits occurred throughout the 24-hour day and lasted in average (±SEM) 5:56 ± 0:22h. The probability of reduced reaction speed, elevated fatigue, and sleepiness levels significantly varied as a function of time-of-day (p≤0.002) and increased with work duration (p≤0.029). These factors interacted such that the effect of work duration on all dependent variables was more prononced when the transit ended at the end of the night. The effect of time-of-day was less and more prononced with shorter and longer transit durations, respectively. A similar interaction was observed for the duration of waking (p>0.001) and time-of-day (p≤0.029) on probability of elevated fatigue and sleepiness. Conclusion: Ship pilots’ performance, fatigue, and sleepiness levels are sensitive to work duration, time awake, and time-of-day. In this group, the worst scores occurred when longer transits ended at the end of the night. Support (If Any): This study was supported by the Laurentian Pilotage Authority and the Corporation des Pilotes du Saint-Laurent Central