March 6, 2014
Shift work
Reuel S. Amdur
More by this author...Anton Aanonsen was a company doctor at an oil enterprise in a small community on the coast of Norway. In his practice he began to see a trend among workers that captured his interest. The number of workers on the night shift who had health problems was relatively high. His examination of the issue led to his 1964 ground-breaking book Shift Work and Health.
Since then, the study of shift work and health has proliferated. The simple explanation of why shift work and night work have consequences for health is that they go counter to the way we are designed. We operate with a clock within us that tells us when to sleep and when to be awake, and it runs on an approximate 24 hour cycle. Light is an important factor in the operation of the clock. The cycle is called a circadian rhythm, from the Latin circā dies, meaning approximately a day.
Scientists writing on the subject find that some workers are more able to adapt to shift work than others. Among difficulties found in shift workers more than in their daytime colleagues are nervous-emotional and gastrointestinal problems such as ulcers. Women have a much higher rate of breast cancer. And as we would expect, shift workers have greater difficulty in taking part in community life. That includes more marital difficulties.
One writer, Torbjorn Akersted, argues that the extent of health problems of shift workers is underreported for two reasons: at least 20% of shift workers cannot handle it and “pack it in”, and shift workers are less likely to seek medical help for a given condition than day workers. Because, it is argued, they are accustomed to dis-ease, they will complain less readily about disease.
J. Carpentier describes the shift worker’s experience as follows: He has sleep that becomes less and less deep, more and more fitful. Fatigue sets in, and he works during the period of the body’s deactivation and rests during its diurnal reactivation. With age and with length of time on shift work, sleep disturbance increases. Martin Moore-Ede adds, “Over 80 per cent of shift workers have serious sleep disruption.”
Shift workers have a tendency to use of drugs, especially hypnotic and sedative drugs, to permit daytime sleep and to keep the worker awake at night. They are more likely to take medication as well for digestion and pain. They also have greater alcohol consumption.
The impact of shift work on functioning is an important matter for consideration. Tilley found that in following a group of workers their reaction time deteriorated as a function of the number of days into the shift and of the amount of time on the task. C.F. Ehret believes that the Three Mile Island accident was exacerbated by operator errors, with strong evidence that poor circadian hygiene was a factor.
Shift work, especially over the long haul, is not for everyone. Yet, some people manage it well. Who can handle it well and who cannot? This is a matter of individual difference. And how will shift work affect the health of the specific worker? Here we need to look at where his Achilles’ heel is. We cannot predict with any likelihood of accuracy. It is only possible to look back to determine cause.
How can shift work be made more worker-friendly? There are three patterns that have been suggested. To begin, it is generally agreed that shifting schedules should never be back, always forward. The three patterns are permanence, a short schedule with frequent shifts, and a long schedule. To justify the short schedule, it is argued that workers never really adjust to a different schedule because on days off they revert back to the normal diurnal pattern. However, it has been found that there is a need for adequate time off to lessen the stress.
Ehret argues against the short schedule because of increased performance deficits in the early morning. He prefers a longer schedule with slow rotation (more than one week, less than five), and with good chrono-hygiene when changes in shifts occur, using programmed feeding, specific kinds of diet, use of coffee and tea and such, as well as social cues. The issue of social cues becomes problematic because restaurants, bars, theatres, churches, clubs, etc. operate on a diurnal schedule.
There are some things that can be done to make shift work less stressful. For example, for day sleepers it is important to create total darkness. It is important that shift workers eat regular meals, not just junk food. Tea and coffee consumption should take into consideration wake and sleep times, and caffeine consumption needs to be limited overall. Melatonin can be used to help in sleep, and alcohol consumption needs to be limited.
From an organizational perspective, does programming for good chrono-hygiene make sense for the bottom line? Charles Czeisler found that the introduction of the long rotation of shifts (no roller coasters) in a Utah factory resulted in a substantial reduction in sick time. Looking at it from the other side, if workers are more alert and less fatigued at times when critical decisions must be made quickly, perhaps such events such as the Three Mile Island incident could be avoided.