Developing a light-based intervention to reduce fatigue and improve sleep in rapidly rotating shift workers

ABSTRACT

Over a quarter of employees in North America and a fifth of those in the European Union do shift work. Working these schedules increases fatigue, sleepiness, and errors at work. In the long term, it may also increase the risk of cardiovascular disease, gastrointestinal problems, and cancer. Some of these consequences may be partly due to circadian misalignment, in which sleep and activity patterns no longer align with one’s circadian rhythms. Previous research has found that controlling light exposure can improve circadian alignment in individuals who work permanent night shifts. However, light-based interventions are rarely tested with rapidly rotating shift schedules, which include more than one type of shift within the same week (e.g., day shifts followed by night shifts). Further, many of the available interventions are seldom used in the workplace and may be less feasible in healthcare environments. In hospitals, the health and safety of both workers and patients can be compromised by increases in fatigue. We thus developed a practical intervention based on circadian and sleep hygiene principles to reduce some of the negative consequences associated with shift work. We then tested this intervention in a feasibility study of 33 nurses working rapidly rotating shifts. The study took place over two separate periods: the control (observation) period and the intervention period. Each period included two to four consecutive night shifts as well as the two days before and after those shifts. Nurses completed daily self-report questionnaires during both periods. During the intervention period, the nurses additionally followed a fatigue reduction plan. The plan involved 40 min of bright light exposure from a portable light box before night shifts, light avoidance using sunglasses after those shifts, and suggestions regarding the ideal times to sleep and nap. Results showed that nurses complied with the large majority of these recommendations. During the intervention period, nurses reported less fatigue, fewer work errors, better and longer sleep, and a more positive mood. Moreover, nurses with a preference for evenings (i.e., later chronotypes) reported the strongest benefits. Though more controlled studies are needed to assess causal mechanisms and long-term effectiveness, these promising results suggest that light-based interventions are feasible and may be effective at reducing fatigue in rapidly rotating shift workers.

KEYWORDS:

• Nursing
• shift work
• rapid rotation
• fatigue
• errors
• sleep
• light
• circadian misalignment

Acknowledgments

We would like to thank Victoria De Braga, Denis Chmoulevitch, Johnny Nahas, and Claire Suisman for assistance with transcribing, and Alain Al Bikaii, Simon Bacon, Alain Biron, Line Breault, Julie Carrier, Élissa Colucci, Charmane Eastman, Steven Grover, Myriam Juda, Mélanie Lavoie-Tremblay, Liza Solomonova, and Meredith Young for feedback. We would also like to thank nurse managers Sylvie Ampleman, Aparna Bhattacharjee, Carole Filteau, Johanne Fiset, Christina Miousse, and Colleen Stone for assistance with recruiting.

Declaration of interest

The authors report no conflicts of interest.

Data availability statement

The Research Ethics Board did not permit data sharing, since some of the data are sensitive (e.g., errors made at work or alcohol consumption) and may be identifiable given the small sample size. Researchers can contact us to run any additional analyses.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research was supported with funds from WorkSafeBC through the Innovation at Work program [RS2016-IG27], PhD scholarships to JO from l’Institut de recherche Robert-Sauvé en santé et en sécurité du travail and the Social Sciences and Humanities Research Council of Canada, and a Master of Science scholarship to DA from the Canadian Institutes of Health Research (CIHR). AR additionally acknowledges funding from CIHR.