Geiger Brown Jeanne, Wieroney Margaret, Blair Lori, Zhu Shijun, Warren Joan, Scharf Steven M, Hinds Pamela S
Center for Health Outcomes Research, University of Maryland School of Nursing, 655 West Lombard St, Baltimore, MD, 21201, USA,
Sleep Breath. 2014 Dec;18(4):731-9. doi: 10.1007/s11325-013-0935-z. Epub 2014 Jan 29.
Sleepiness during the work shift is common and can be hazardous to workers and, in the case of nurses, to patients under their care. Thus, measuring sleepiness in occupational studies is an important component of workplace health and safety. The Karolinska Sleepiness Scale (KSS) is usually used as a momentary assessment of a respondent's state of sleepiness; however, end-of-shift measurement is sometimes preferred based on the study setting. We assessed the predictive validity of the KSS as an end-of-shift recall measurement, asking for "average" sleepiness over the shift and "highest" level of sleepiness during the shift.
Hospital registered nurses (N=40) working 12-h shifts completed an end-of-shift diary over 4 weeks that included the National Aeronautical and Space Administration Task Load Index (NASA-TLX) work intensity items and the KSS (498 shifts over 4 weeks). Vigilant attention was assessed by measuring reaction time, lapses, and anticipations using a 10-min performance vigilance task (PVT) at the end of the shift. The Horne-Ostberg Questionnaire, Epworth Sleepiness Scale, General Sleep Disturbance Scale, and Cleveland Sleep Habits Questionnaire were also collected at baseline to assess factors that could be associated with higher sleepiness. We hypothesized that higher KSS scores would correlate with vigilant attention parameters reflective of sleepiness (slower reaction times and more lapses and anticipations on a performance vigilance task) and also with those factors known to produce higher sleepiness. These factors included the following: (1) working night shifts, especially for those with "morningness" trait; (2) working sequential night shifts; (3) having low physical and mental work demands and low time pressure; (4) having concomitant organic sleep disorders; and (5) having greater "trait" sleepiness (Epworth Sleepiness Scale). Linear mixed models and generalized linear mixed models were used to test associations that could assess the predictive validity of this format of administering the KSS.
Greater sleepiness, as measured by higher KSS scores, was found on shifts with nurses working night shift, the third sequential night compared to the first, those with sleep disorder symptoms (especially insomnia), and in nurses with trait sleepiness on the Epworth scale. Less sleepiness (lower KSS scores) was seen in shifts with a high level of time pressure and in nurses with a biologic predisposition to be more alert in the morning (morningness trait) who worked the day shift.
We found partial support for using the Karolinska Sleepiness Scale in the recalled format based on our multiple tests of predictive validity.
轮班期间的困倦很常见，这对工人来说可能是危险的，对于护士而言，还会对他们护理的患者构成危险。因此，在职业研究中测量困倦程度是工作场所健康与安全的重要组成部分。卡罗林斯卡困倦量表（KSS）通常用于即时评估受访者的困倦状态；然而，根据研究设置，有时更倾向于在轮班结束时进行测量。我们评估了KSS作为轮班结束时回忆性测量的预测效度，询问了整个轮班期间的“平均”困倦程度以及轮班期间“最高”的困倦水平。
医院注册护士（N = 40）进行12小时轮班，在4周内完成了一份轮班结束时的日记，其中包括美国国家航空航天局任务负荷指数（NASA - TLX）工作强度项目和KSS（4周内共498个班次）。在轮班结束时，通过使用10分钟的绩效警觉任务（PVT）测量反应时间、失误和预期来评估警觉注意力。在基线时还收集了霍恩 - 奥斯特伯格问卷、埃普沃思嗜睡量表、一般睡眠障碍量表和克利夫兰睡眠习惯问卷，以评估可能与较高困倦程度相关的因素。我们假设较高的KSS分数将与反映困倦的警觉注意力参数（较慢的反应时间以及在绩效警觉任务中更多的失误和预期）相关，也与那些已知会导致较高困倦程度的因素相关。这些因素包括：（1）上夜班，尤其是那些具有“晨型”特质的人；（2）连续上夜班；（3）身心工作需求低且时间压力小；（4）伴有器质性睡眠障碍；（5）具有较高的“特质”嗜睡（埃普沃思量表）。使用线性混合模型和广义线性混合模型来测试关联，以评估这种KSS施测形式的预测效度。
通过较高的KSS分数测量发现，在上夜班的护士班次、与第一个连续夜班相比的第三个连续夜班、有睡眠障碍症状（尤其是失眠）的护士班次以及埃普沃思量表上具有特质嗜睡的护士中，困倦程度更高。在时间压力高的班次以及具有早晨更警觉的生物学倾向（晨型特质）且上白班的护士中，困倦程度较低（KSS分数较低）。
基于我们对预测效度的多次测试，我们发现对于以回忆形式使用卡罗林斯卡困倦量表有部分支持。
