In this article, Jane Coombs gives an introduction to the key issues and conditions raised by tiredness at work, the tools available to measure the problem, and the role of occupational health in protecting affected employees.
“Head Nurse Parker!” I opened my eyes to see the night matron glaring at me in the twilight world of the nurses’ night station. I was sitting with my head resting on my cupped hands, elbows conveniently resting on a pile of fluid charts. It was 2am in January 1975, and I had fallen asleep sitting upright.
I tried to remember the name, date of birth and diagnosis of my 22 patients as the night matron escorted me round the ward, getting increasingly angry as my mind emptied itself of anything remotely useful.
I had been “in charge” for the past nine nights, starting at 8.30pm and finishing at 8am, working through Christmas and Boxing Day. That night, New Year’s Eve, was my last working night.
Nowadays, employers have a duty to take all practicable steps to ensure that employees are safe at work, and fatigue is a workplace hazard that they must manage.
One thing a night shift would not include is giving out a large glass of sherry to all head nurses to celebrate the new year, especially to those who were already fatigued with eight nights’ work under their belts and struggling to sleep through the celebrations in the nurses’ quarters.
What is fatigue?
Fatigue is a general term used to describe a wide variety of conditions, but is generally accepted as feeling very tired, weary or sleepy as a result of insufficient sleep, prolonged mental or physical work, or extended periods of stress or anxiety.
Boring or repetitive tasks can intensify feelings of fatigue. Fatigue can also be described as either acute (usually reversed by sleep and relaxation) or chronic (the constant, severe state of tiredness not relieved by rest).
Guidance from the Royal College of Nursing on shift work published in 2012 sets out how shift work affects the occupational health of workers (especially health workers) – although the guidance is useful for anyone wanting to protect and enhance the health of shift workers generally.
Humans follow an “internal” or “biological clock” cycle of sleep, wakefulness and alertness. Although these “circadian” rhythms are influenced by external clues such as the sun setting and rising, it is the brain that sets the pattern. Most cycles are 23 to 25 hours long and there are natural dips or periods when workers feel tired or less alert, even among those who are well rested.
Health and safety
Many negative health aspects are associated with shift work, including an increase in accidents while on the job, reduced duration and quality of sleep, fatigue, and being less alert when performing duties (Smith et al, 1998; van der Hulst, 2003). The worker may experience decreased reaction times and poorer work performance (Scott et al, 2006). Most recently, shift work has also been implicated in breast cancer.
Fatigue at work has been identified as a contributory factor to some of the most significant disasters of our time: the Three Mile Island accident in Pennsylvania; the Chernobyl nuclear power plant accident in Russia (Suzuki et al, 2005); and the grounding of the oil tanker Exxon Valdez off the coast of Alaska (Wadsworth et al, 2006).
Measuring fatigue levels is not easy as it varies from person to person; therefore, it is difficult to isolate the actual effect of fatigue on accident and injury rates in business. However, some research studies have shown that when workers have slept for less than five hours before work or when workers have been awake for more than 16 hours, their chance of making mistakes at work due to fatigue are significantly increased. Further, Alberta Human Resources and Employment reports that most accidents occur when people are most likely to want sleep, ie between midnight and 6am, and between 1pm and 3pm.
Several instruments that have been developed to measure fatigue in the workplace are detailed below.
Health and Safety Executive fatigue index
Acknowledging the issues of fatigue on health and safety performance, the Health and Safety Executive (HSE) developed the fatigue index (FI) in 2006 to measure the effects of a rotating shift pattern and the requirement to provide guidance in support of the Railway (Safety Critical Work) Regulations. Since then, the FI has been increasingly used in other areas, eg by the police, nuclear and chemical industries. It has been modified as new information on fatigue and risk has become available.
The FI looks at five factors associated with the development of fatigue, namely: time of day; shift duration; rest periods; breaks; and cumulative fatigue. The scores from each are added to provide an overall index for the pattern of work.
Epworth sleepiness scale
The Epworth sleepiness scale (ESS) is an eight-point questionnaire that provides a measure of general daytime sleepiness assessed by an individual rating their usual chances of dozing or falling asleep in eight different situations.
Causes of fatigue at work
There are many causes of fatigue. Work-related factors may include: long work hours; prolonged periods of physical or mental activity; insufficient break time between shifts; inadequate rest; excessive stress; or a combination of these factors. Sometimes, a sleep disorder may also cause fatigue. (See table Health issues linked to shift work, sleep and fatigue for a list of health issues that could affect sleep or increase fatigue.)
Keeping workers alert
Fatigue is known to increase with:
- dim lighting;
- limited visual acuity (eg due to weather);
- high temperatures;
- loud noises;
- high comfort;
- tasks that must be sustained for long periods of time; and
- tasks that are long, repetitive, difficult, boring or monotonous.
Workplaces can help by providing environments that have good lighting, comfortable temperatures and reasonable noise levels. Work tasks should provide a variety of interest and should change throughout the shift. If extended hours and overtime are common, remember to consider the time required for employees to commute from home, and workers should allow time for meal preparation, eating and socialising. Workplaces may also wish to consider providing:
- onsite accommodation;
- prepared meals for workers; and
- facilities where employees can take a nap before driving home.
Research into shift work and its effects on health have resulted in a set of ergonomic recommendations that should be taken into account, and include:
- minimise permanent night shifts;
- minimise sequence of night shifts, only two to four shifts in succession;
- consider shorter night shifts;
- avoid quick changeovers;
- plan rotas with some free weekends;
- avoid overlong work sequences;
- rotate forward (ie clockwise rotation morning/evenings/nights); and
- avoid early starts.
OH’s role in dealing with fatigue
Employers have a duty under the Working Time Regulations (1998) to offer a health assessment to those who work at night. The employee is not obliged to accept the offer or even to fill in a health questionnaire form, but employers must offer it. This system of offering a health assessment has sometimes been misunderstood, though, with some OH providers using the completed health questionnaire as a means of assessing whether or not someone is actually fit to work nights. The assessment has resulted in workers being forced onto a different shift pattern because of perceived health risks. In my view, this is not the purpose of the health assessment.
Healthcheck to include a night workers’ health assessment
What is also interesting about the health assessment is that no one has specified what it actually consists of, and some OH services have set up an appointment with an employee for a full assessment, including blood pressure, cholesterol, height and weight advice and urine sampling, while others have only offered a telephone consultation.
This is one area of health checking where more clarification is needed and employees need to know exactly what will occur once they “sign up” for this supposedly helpful check. There is also the chance that workers may withdraw consent if they do not like the conclusions.
It should be recognised that shift work may suit an individual worker even though there are obvious issues with health and fatigue in general. In my experience, workers quickly adapt to the financial benefits of working night shifts with the “three days on, four days off” pattern, allowing workers to take on second jobs (worked around their main job) to supplement incomes. Trying to change shift patterns can be fraught with industrial relations issues, especially if there is extra money for working unsocial hours or weekends and public holidays. Workers come to rely on this and are happy to sacrifice their poor health in order to care for their families.
Education is key
In organisations where judgment, quick reactions and safety-critical roles are key, top management, as well as the workers, must be educated about the risks of working long hours and dealing with associated fatigue. This must include ways to avoid adverse outcomes and errors, and signs and symptoms of both long- and short-term health issues.
Constant vigilance for signs of fatigue and its health effects in workers is needed by management and OH for organisations that use extended shifts and shift work. Despite the increased opportunities for leisure time on 12-hour and longer shift durations, the longer workday has the potential to contribute to human error and accidents in the workplace. After all, if I had had a medical emergency on New Year’s Eve back in 1975, would I have been able to cope? I like to think I would have done, but I am glad I was not tested.
Jane Coombs is an OH adviser at Working Well Solutions.
|Health issues linked to shift work, sleep and fatigue|
|Insomnia||Difficulty falling asleep, or cannot stay asleep for a full night. Waking during the night, waking too early, not able to fall asleep at night, or having difficulty getting back to sleep if woken. Insomnia can be both short term (in response to a stressful event or change in environment) or long term.|
|Sleep apnoea||A breathing disorder in which there are brief interruptions (lasting a minimum of 10 seconds) in breathing during sleep. The frequent interruptions makes sleep unrestful. Often accompanied by early morning headaches and excessive daytime sleepiness.|
|Narcolepsy||Sudden sleep “attacks” where a person will have an uncontrollable urge to sleep many times in one day.|
|Substances||Nicotine, caffeine and alcohol can affect the quality of sleep. Alcohol may shorten the time to fall asleep, but disrupt sleep later in the night. Nicotine also can disrupt sleep and reduce total sleep time. Over-the-counter medications or prescriptions may also affect sleep, for example, long-acting benzodiazepines may contribute to daytime sleepiness.|
|Diabetes||Particularly where treatment with insulin injections on a
strict timetable is required.
|Heart and circulatory||Affecting physical stamina levels.|
|Stomach and intestinal||For example, ulcers and other conditions where the timing
of meals is particularly important.
|Chest/breathing problems||Chronic chest disorders where night-time symptoms may interfere with sleep.|
|Medication timetable||Medical conditions requiring medication on a strict timetable. Shift work can interrupt the programme.|
|Treatments||Cancer treatments can affect fatigue levels.|
|Ageing||Between 40 and 45 years of age, changes occur in the internal biological clock that affect the coordination between various circadian rhythms, such as core body temperature, hormone levels and the sleep/wake cycle, causing sleep to become more fragile and easily disrupted, particularly on night shifts.|
|Interruptions in sleep||New parents, or those suffering from environment or housing issues, may suffer from sleep interruptions.|
|Long-term health conditions||For example multiple sclerosis, motor neurone disease, Parkinson’s, and seasonal affective disorder.|
|Mental health||Work events can be emotionally tiring and increase fatigue, such as regular criticism or the pressure to complete a task to a deadline. Domestic events can also cause distress and lead to fatigue, eg bereavement or personal conflicts.|
|Pregnancy||Frequent trips to the toilet, uncomfortable positioning and increasing girth may all disrupt sleep.|
|Jet lag||For those who take frequent business trips overseas, jet lag consists of excessive sleepiness and a lack of daytime alertness.|
|Shift-work sleep disorder||This sleep disorder affects people who frequently rotate shifts or work at night.|
Royal College of Nursing (2012). “A shift in the right direction: RCN short guidance on the occupational health and safety of shift working nurses and health care assistants”.
Scott LD, Rogers AE, Hwang WT, Zhang Y (2006). “Effects of critical care nurses’ work hours on vigilance and patients’ safety”. American Journal of Critical Care; 13(1), pp.30-37.
Smith L, Folkard S et al (1998). “Work shift duration: a review comparing eight hour and 12 hour shift systems”. Occupational and Environmental Medicine; 55, pp.217-229.
Spencer MB, Robertson KA, Folkard S (2006). The development of a fatigue/risk index for shiftworkers. HSE.
Suzuki K, Ohida T, Kaneita Y, Yokoyama E and Uchiyama M (2005). “Daytime sleepiness, sleep habits and occupational accidents among hospital nurses”. Journal of Advanced Nursing; 52(4), pp.445-453.
van der Hulst M (2003). “Long work hours and health”. Scandinavian Journal of Work, Environment and Health; 29, pp.171-188.
Wadsworth EJ, Allen PH, Wellens BT, McNamara RL and Smith AP (2006). “Patterns of fatigue among seafarers during a tour of duty.” American Journal of Industrial Medicine; 49(10), pp.836-844.
Wedderburn A (1991). “Guidelines for shiftworkers”. Bulletin of European Foundation for the Improvement of Living and Working Conditions, Dublin.