Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
Department of Ergonomics, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Sleep Breath. 2022 Dec;26(4):1759-1769. doi: 10.1007/s11325-021-02526-6. Epub 2022 Jan 11.
Optimal cognitive performance might prevent vehicle accidents. Identifying time-related circadian and homeostatic parameters having an impact on cognitive performance of drivers may be crucial to optimize drivers' performance.
In this prospective study conducted on bus drivers, two drivers alternated driving during a 24-h round trip and were accompanied by an interviewer. Each driver was tested using Karolinska Sleepiness Scale (KSS) and the reversed digit span Wechsler Working Memory test before the start of his shift and then every 6 h during a "work/driving" day. Psychomotor Vigilance Task (PVT) was assessed before and after the journey. Linear mixed model was used to explore the factors affecting cognitive performance and sleepiness in univariate and multivariate analysis.
Among 35 bus drivers, the effect of time of day on working memories was statistically significant (p = 0.001), with the lowest working memory scores at 04:00 am (± 1). The highest score of subjective sleepiness was also at 04:00 am (± 1). The time on task parameter affected sleepiness significantly (p = 0.024) and sleepiness was significantly associated with decreased working memory. Psychomotor Vigilance Task reaction time mean and the number of minor lapses were significantly increased after the journey, which suggested decreased vigilance. In multivariable analysis, a longer interval between the beginning of working hours and testing time (B (95% CI) = 15.25 (0.49 to 30), p = 0.043) was associated with higher (i.e., slower) PVT reaction time mean.
These results suggest that optimizing bus drivers' working schedules may improve drivers' sleepiness and cognitive performance and thus increase road safety.
最佳认知表现可能有助于预防车辆事故。确定对驾驶员认知表现有影响的与时间相关的昼夜节律和内稳态参数，对于优化驾驶员的表现可能至关重要。
在这项对公共汽车司机进行的前瞻性研究中，两名司机在 24 小时的往返行程中交替驾驶，并由一名采访者陪同。每位司机在轮班前和轮班期间每 6 小时使用 Karolinska 睡眠量表（KSS）和反向数字跨度韦氏工作记忆测试进行测试。在旅程前后评估了精神运动警觉任务（PVT）。使用线性混合模型在单变量和多变量分析中探索影响认知表现和嗜睡的因素。
在 35 名公共汽车司机中，时间对工作记忆的影响具有统计学意义（p=0.001），凌晨 4 点（±1）的工作记忆得分最低。主观嗜睡的最高得分也在凌晨 4 点（±1）。任务时间参数对嗜睡有显著影响（p=0.024），嗜睡与工作记忆下降显著相关。精神运动警觉任务反应时间平均值和小失误次数在旅程后显著增加，表明警觉性下降。在多变量分析中，工作时间开始与测试时间之间的间隔较长（B（95%CI）=15.25（0.49 至 30），p=0.043）与 PVT 反应时间平均值较高（即较慢）相关。
这些结果表明，优化公共汽车司机的工作时间表可能会改善司机的嗜睡和认知表现，从而提高道路安全。
