In their paper “Managing fatigue: It’s about Sleep” (Sleep Medicine Reviews, 2005, 9) Drew Dawson and Kirsty McCulloch present a case for “shift(ing) away from prescriptive HOS (hours of service) approaches to one in which fatigue is no longer managed as an industrial or labour relations issue but rather, as part of an organization’s overall SMS (safety management system)”.
They propose a Prior Sleep/Wake Model arguing that “fatigue is better estimated from prior sleep/wake behavior than from patterns of work.” This model requires a determination of the amount of sleep had in the last 24 hours, the amount of sleep had in the last 48 hours and the amount of time awake from waking to the end of work.
Citing related research, they conclude that general parameters for this model would be as follows:
If an individual has had less than 5 hours of sleep in the last 24 hours and less than 12 hours of sleep in the last 48 hours as well as having been awake for more hours than the total sleep time in the previous 48 hours, than they would be considered at risk for a fatigue error or accident.
Though they set these out as general parameters, they caution that for some tasks and in some circumstances, these may not be adequate or may be over cautious. More industry and task-specific research needs to be done to determine more specific guidelines
Strategies for Health and Safety
Provide education about fatigue and how to recognize it. Include all employees, be they shift workers or regular day employees.
Ensure that your organizational culture supports safety, not just in word, but in deed as well. Ensure that staffing levels are optimum and that overtime is minimized.