A phase-advanced, extended sleep paradigm to increase sleep duration among early-morning shift workers: a preliminary investigation

Abstract

Yeung J, Sletten TL, Rajaratnam SM. A phase-advanced, extended sleep paradigm to increase sleep duration among early-morning shift workers: a preliminary investigation. Scand J Work Environ Health. 2011;37(1):62-69 Objective In this preliminary study, using a within-subjects design, we investigated the effects of phaseadvancing bedtime on sleep quality and duration among early-morning shift workers. MethodsThe sleep-wake patterns of 16 healthy volunteers who work shifts with start times between 04.00-07.30 hours were recorded by wrist actigraphy and sleep diary for two weeks. In week 1, we assessed the habitual sleep-wake pattern. In week 2, participants were required to advance their bedtime to 10 hours before the start of the morning shift. Subjective sleepiness was assessed three times each day.Results Total sleep time was longer (1.4 hours) for sleep episodes that occurred prior to days off from work compared to those prior to early-morning shifts. The intervention resulted in bedtime being advanced by 1.5 hours and total sleep time being increased by 1.0 hour, without changes to the latency, efficiency or quality of sleep, or activity level during the sleep episode. A small reduction in daytime sleepiness was found during the intervention phase for assessments taken just prior to bedtime.Conclusions Sleep duration among early-morning shift workers is substantially truncated due to their work schedules. When participants were instructed to advance their bedtime for one week, these individuals were able to increase sleep duration without affecting sleep quality. We suggest longer term studies testing the efficacy of sleep extension as a low-cost, behavioral intervention for improving health and safety outcomes among earlymorning shift workers.

Sleep Quantity and Quality of Ontario Wildland Firefighters Across a Low-Hazard Fire Season

“… 64 – 66 Good design of work hours would include later shift start times (≥7 am ) and more time between shifts (≥12 hours) when possible. 67 These guidelines may be easier to implement during Project Fire rather than Initial Attack deployments due to the nature of the fire suppression activities. For Initial Attack suppression, it may be wise to limit the shortened sleep periods as much as possible to reduce performance deficits and fatigue-related errors in judgment.…”

Non-Pharmacological Interventions to Improve Chronic Disease Risk Factors and Sleep in Shift Workers: A Systematic Review and Meta-Analysis

“…Lastly, one study evaluated the effectiveness of prescribing a bedtime ten hours prior to the start time of the following shift. The prescription of bedtime resulted in increased objective sleep duration and increased subjective sleep duration and quality [116]. Further, the sample for this study was small (n = 16) but did investigate a range of occupations (manufacturing, customer service, nursing, and public service).…”

“…This is not surprising-while shift work may be a common feature for these workers, individual differences in occupation, sociodemographic characteristics, job demands, and health status likely call for unique interventions. Broadly, objective sleep measures were improved by controlled light exposure including intermittent bright light [123,130], bright light and light-blocking goggles [119,126,129,130], light-blocking goggles alone [125], schedule change which increased recovery periods [87,92,96] and prescriptive sleep scheduling [116]. Subjective measures of sleep were improved by a change to 12 h shifts (e.g., two-shift system) [70,88,89,91,93,97], a change to forward rotation schedules [78,80,83,90], increased rest or recovery periods [75,79], individualised behavioural intervention aimed at improving sleep and fatigue [106,115], and some complementary therapies (e.g., electrical acupoint stimulation and aromatherapy massage) [131,134].…”

Effects of dynamic ambient lighting on female permanent morning shift workers

“…Morning shifts starting between 04.00 and 07.00 hours are particularly associated with disturbances in the sleep-wake pattern during and outside shifts. [1][2][3] Yeung et al 4 have shown that total sleep time was reduced by 1.4 hours during morning shift work. Folkard et al 5 found that for a shift worker to get a full 8-hours sleep period before their morning shift they would have to leave home at 8 o'clock in the morning.…”