Corrigendum to ‘Sleep and sleepiness in shift-working tram drivers’[Applied Ergonomics Sleep and sleepiness in shift-working tram drivers 88 (2020) 103153]

Recurrent On-Duty Sleepiness and Alertness Management Strategies in Long-Haul Airline Pilots

Introduction We examined whether long-haul airline pilots without recurrent on-duty sleepiness obtain more prior sleep and use more effective in-flight alertness management strategies than their colleagues with recurrent on-duty sleepiness. Methods There were 51 pilots who flew at least twice from Helsinki to Asia. Of them, 44 flew at least twice back to Helsinki following 1 local night. On-duty sleepiness was measured by the Karolinska Sleepiness Scale (KSS), alertness management strategies by a diary, and sleep by a diary and activity monitor. Pilots who rated KSS ≥ 7 on each, some, or none of the flights were classified as "regularly", "sometimes", and "never" sleepy, respectively. This …

Self-reported reasons for on-duty sleepiness among commercial airline pilots

Experimental and epidemiological research has shown that human sleepiness is determined especially by the circadian and homeostatic processes. The present field study examined which work-related factors airline pilots perceive as causing on-duty sleepiness during short-haul and long-haul flights. In addition, the association between the perceived reasons for sleepiness and actual sleepiness levels was examined, as well as the association between reporting inadequate sleep causing sleepiness and actual sleep-wake history. The study sample consisted of 29 long-haul (LH) pilots, 28 short-haul (SH) pilots, and 29 mixed fleet pilots (flying both SH and LH flights), each of whom participated in a…

Cognitive behavioural therapy interventions for insomnia among shift workers: RCT in an occupational health setting

Abstract Introduction The aim of the study was to compare the effectiveness of cognitive behavioural therapy interventions for insomnia (CBT-I) to that of a sleep hygiene intervention in a randomized controlled design among shift workers. We also studied whether the features of shift work disorder (SWD) affected the results. Methods A total of 83 shift workers with insomnia disorder were partially randomized into a group-based CBT-I, self-help CBT-I, or sleep hygiene control intervention. The outcomes were assessed before and after the interventions and at 6-month follow-up using questionnaires, a sleep diary, and actigraphy. Results Perceived severity of insomnia, sleep-related dysfunction…

Sleep restriction for the duration of a work week impairs multitasking performance

It is important to develop shift schedules that minimise the chance for sleep-related human error in safety-critical domains. Experimental data on the effects of sleep restriction (SR) play a key role in this development work. In order to provide such data, we conducted an experiment in which cognitively demanding and long-duration task performance, simulating task performance at work, was measured under SR and following recovery. Twenty healthy male volunteers, aged 19-29 years, participated in the study. Thirteen of them had first two baseline days (8-h sleep opportunity per day), then five SR days (4-h sleep) and finally two recovery days (8-h sleep). Seven controls were allowed to sleep…

Sleep and sleepiness in shift-working tram drivers

Driver sleepiness contributes to traffic accidents. However, sleepiness in urban public transport remains an understudied subject. To fill this gap, we examined the sleepiness, sleep, and on-duty sleepiness countermeasures (SCMs) in 23 tram drivers working morning, day, and evening shifts for three weeks. Sleepiness was measured using Karolinska Sleepiness Scale (KSS). Nocturnal total sleep time (TST) was measured with wrist actigraphy. SCMs and naps were self-reported with a smartphone application. Caffeine and napping were considered effective SCMs. Severe sleepiness (KSS >= 7) was observed in 22% of shifts with no differences between shift types. Rest breaks were associated with slight r…

On-Road Study of Fatigue Management Strategies in Long-Haul Truck Drivers

The current study investigated what strategies long-haul truck drivers use to mitigate fatigue at the wheel. A group of 52 truck drivers participated in the study in which drivers’ fatigue at the wheel was measured by a well-validated self-rating scale (the Karolinska Sleepiness Scale) and the use of fatigue countermeasures by a diary for a period of two consecutive workweeks including day and night-time trips. Results showed that the drivers more frequently used fatigue countermeasures while fatigued at the wheel but most of these countermeasures, with the exception of caffeine, can be regarded as inefficient (e.g., opening a window). The results indicate that long-haul truck drivers resp…

The self-reported stress and stressors in tram and long-haul truck drivers

Work stress may compromise professional drivers’ health and driving capacity. Differences between driver groups in terms of on-duty stress are understudied. Therefore, we examined self-reported stress (Stockholm University Stress Scale) of shift-working tram and long-haul truck drivers (n = 75) across 2–3 weeks. Furthermore, stressors were self-reported retrospectively and categorised as related to the job, driving conditions, personal, or other causes. Stress levels were generally low, but moderate to high stress (≥6) was more frequently reported among the tram drivers. Stressors related to the job (54%) and driving conditions (19% of all shifts) were frequently reported among the tram and…

Effects of cumulative sleep restriction on self-perceptions while multitasking

Summary This study addressed a rarely studied question of self-perceptions of performance and overall functional state during cumulative sleep restriction and the ensuing recovery period. Twenty healthy male volunteers, aged 19–29 years, were divided into a sleep restriction group (n = 13) and a control group (n = 7). On the first 2 nights, the sleep restriction group had an 8-h sleep opportunity that was restricted to 4 h for the next 5 nights, and then restored to 8 h for the last 2 nights. The control group had an 8-h sleep opportunity each night. Each day participants accomplished 50-min multitask sessions and gave self-ratings in their connection. Similar to our previous findings on mu…

Sleep and alertness in shift work disorder: findings of a field study

Purpose Although shift work disorder (SWD) affects a major part of the shift working population, little is known about its manifestation in real life. This observational field study aimed to provide a detailed picture of sleep and alertness among shift workers with a questionnaire-based SWD, by comparing them to shift workers without SWD during work shifts and free time. Methods SWD was determined by a questionnaire. Questionnaires and 3-week field monitoring, including sleep diaries, actigraphy, the Karolinska Sleepiness Scale (KSS), EEG-based sleep recordings, and Psychomotor Vigilance Tasks (PVT), were used to study 22 SWD cases and 9 non-SWD workers. Results The SWD group had a shorter …

The self-reported causes of sleepiness in shift-working tram and truck drivers

Identifying the causes of sleepiness in various safety-critical work environments is neces-sary for implementing more efficient fatigue management strategies. In transportation, little is known about drivers' own perceptions of these causes. Therefore, we instructed shift-working tram (n = 23) and long-haul truck drivers (n = 52) to report at the end of their shifts what made them sleepy if they felt so. These self-reports, measured on-duty sleepiness, and sleep amounts were recorded on every shift over a period of 2-3 weeks per driver. The causes of sleepiness were queried with smartphone applications and sleep logs. Sleepiness was measured with the Karolinska Sleepiness Scale (KSS) and sl…

Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men

Purpose Sleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men. Methods After two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed.…