What is the worst shift schedule?

Anyone who has worked shift-work for any period of time knows how hard it can be.  But what’s the worst schedule of all?  It has got to be the counter-clockwise fast rotating schedule.  This schedule never gives your body-clock time to adjust to sleeping at a new phase and what’s worse, is that it goes against the natural clockwise progression of your circadian rhythms.

Some recent research has shown that, when compared to the clockwise rotating shift schedule, the counter-clockwise one leads to less refreshing sleep and more fatigue [1]. When fatigue is higher, reaction times get longer, and attention and judgment get poorer [2].

Tired businesswoman at desk during overtime

In one version of the fast counter-clockwise schedules I assessed, after a succession of earlier and earlier shifts, you worked an early day shift from 05:00 hrs to 14:00 hrs. This was followed by almost two days off before your midnight shift.  It was like a built-in weekend right in the middle of your schedule…and that was the problem. Instead of using that two days off to work on adjusting your circadian rhythms and getting enough sleep, most shift-workers use that time off to deal with their family and personal commitments. Which, of course, leads to less sleep and even more fatigue, slower reaction times and worse attention and judgment.

So what do you do?  My rule is to prioritize biology. This means that schedulers should avoid the counter-clockwise rotations and instead, set up clockwise rotating schedules. Better still, avoid the need for circadian adjustment altogether by keeping shift-workers on a fixed shift for as long as possible.

Article written by Clinton Marquardt, MA, RPSGT – Human Fatigue Specialist

Clinton is a Human Fatigue Specialist. He works with 24/7 operations organizations, safety critical organizations and progressive organizations that genuinely care about their people to improve performance, health & well-being and reduce fatigue related risks. Contact Clinton at 613-482-0837 or at clintm@sleepanddreams.com.

[1] See for examples:
(A) Brooks, I., & Swailes, S., (2002). Analysis of the relationship between nurse influences over flexible working and commitment to nursing. Journal of Advanced Nursing, 38(2), 117-126.
(B) Hossain, J., Reinish, L., Heslegrave, R., Hall, G., Kayumov, L., Chung, S., Bhuiya, P., Jovanovic, D., Huterer, N., Volkov, J., & Shapiro, C. (2004). Subjective and objective evaluation of sleep and performance in daytime versus nighttime sleep in extended-hours shift-workers at an underground mine. Journal of Occupational and Environmental Medicine, 46(3), 212-226.
(C) Winwood., P., Winefield, A., & Lushington, K. (2006). Work related fatigue and recovery: The contribution of age, domestic responsibilities and shift work. Journal of Advanced Nursing, 56(4), 438-449.
[2] See for examples:
(A) Samaha, E., Lal, S., Samaha, N., & Wyndham, J. (2007). Psychological, lifestyle and coping contributors to chronic fatigue in shift-worker nurses. Journal of Advanced Nursing, 59(3), 221-232.
(B) Takeyama, H., Itani, T., Tachi, N., Sakamura, O., Murata, K., Inoue, T., Takanishi, T., Suzumura, H., & Niwa, S. (2005). Effects of shift schedules on fatigue and physiological functions among firefighters during night duty. Ergonomics, 48(1), 1-11.
(C) Wynwood., P., Winefield, A., & Lushington, K. (2006). Work related fatigue and recovery: The contribution of age, domestic responsibilities and shift work. Journal of Advanced Nursing, 56(4), 438-449.

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