De Valck Elke, Quanten Stijn, Berckmans Daniël, Cluydts Raymond
Department of Cognitive and Biological Psychology, Faculty of Psychology and Educational Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
Scand J Work Environ Health. 2007 Feb;33(1):51-7. doi: 10.5271/sjweh.1064.
The objectives of this study were to examine simulator driving and subjective sleepiness after morning, afternoon, and night shifts and to compare these differences, as well as objective stress, between a fast-forward and a slow-backward rotating shift system.
The participants were male volunteers working in a chemical plant, 18 in a slow-backward rotating system and 18 in a fast-forward rotating system. All of the participants performed a driving simulator test and subjectively estimated sleepiness after a night, afternoon, and morning shift. Salivary cortisol samples, as indicators of the objective stress level, at the beginning of the workweek-after the second morning shift-were compared between the two rotating shift systems.
Lane drifting was higher after a night shift than after an afternoon shift. No effect of rotation system on driving performance could be shown. The subjective sleepiness scores were significantly higher in the slow-backward rotating group than in the fast-forward rotating group. A significant effect of shift type was also observed, with lower levels of sleepiness after the afternoon shift than after the morning and night shifts. Salivary cortisol samples taken at the start of the workweek did not significantly differ between the fast-forward and the slow-backward rotation shift systems.
This study indicated that shift type is more important than shift schedule-direction and speed of rotation-in determining driving performance. Performance seemed to be threatened mostly by a night shift and the least by an afternoon shift. In contrast, subjective sleepiness also differed between rotation groups and indicated an advantage of the fast-forward rotation system. The exploratory salivary cortisol measurements suggested that the shift systems studied do not differ in the level of stress they induce, that is to say at the beginning of the workweek.
本研究的目的是检查早班、中班和夜班后的模拟驾驶情况和主观嗜睡程度，并比较快速向前和缓慢向后轮班系统之间的这些差异以及客观压力。
参与者为化工厂的男性志愿者，18人在缓慢向后轮班系统中工作，18人在快速向前轮班系统中工作。所有参与者在夜班、中班和早班后都进行了驾驶模拟器测试，并主观估计了嗜睡程度。在工作周开始时（第二个早班之后），比较了两个轮班系统中作为客观压力水平指标的唾液皮质醇样本。
夜班后的车道偏移比中班后更高。未显示轮班系统对驾驶性能有影响。缓慢向后轮班组的主观嗜睡评分显著高于快速向前轮班组。还观察到轮班类型有显著影响，中班后的嗜睡程度低于早班和夜班后。在工作周开始时采集的唾液皮质醇样本在快速向前和缓慢向后轮班系统之间没有显著差异。
本研究表明，在确定驾驶性能方面，轮班类型比轮班时间表（方向和旋转速度）更重要。驾驶性能似乎主要受到夜班的威胁，受到中班的威胁最小。相比之下，不同轮班组之间的主观嗜睡程度也有所不同，表明快速向前轮班系统具有优势。探索性的唾液皮质醇测量表明，所研究的轮班系统在诱导的压力水平方面没有差异，也就是说在工作周开始时。
