Some of the Issues
The range of work hours is continuing to grow and an estimated 20% of workers world-wide work some form of shift-work (18). In contrast, only about 3% of the workforce were shift-workers in 1904 (20). Shift-work is a pattern of work that includes more than one scheduled work period in a work day, or when the work period is scheduled outside the normal business day (approx. 09:00 to 17:00 hrs.) including evening, night and weekend work periods (18). About 23% of Canadians work shift-work (18).
Improperly managed shift-work can have disastrous consequences. The cause of some of the world’s worst accidents can be traced back to shift-work problems. For example, the United Airlines flight # 2860 on December 18, 1977 crashed near Salt Lake City Utah after the pilots had worked a long haul shift throughout the night. More than 200 passengers and crew on board perished. The Three Mile Island nuclear plant disaster, the Davis-Besse nuclear plant accident in Ohio, and the Chernobyl crisis in the former Soviet Union all had their roots in shift-work.
There is also a personal toll to be paid by shift-workers. Job satisfaction is lower for shift-workers than day workers in spite of 30 – 40% higher salaries, and they are always looking for day jobs (3). Job satisfaction is the number one predictor of life span (13) which means that shift-workers might have shorter life-spans than day workers.
Not only do their mortality rates differ, but the health they experience while working shifts is poorer. For example, sleep disturbances are a frequently reported problem of shift-workers (1) and the digestive, locomotor disturbances, cardiovascular, and respiratory problems that start during shift-work persist in the retired shift-workers (15).
Organizations instituting shift-work schedules in hopes of increased productivity and profit may actually be hurt by the change since cognitive functioning is impaired by shift-work (2 & 7). In addition, psychomotor performance is compromised during rotating shift schedules. Some shift-workers, including pilots, actually demonstrate increased physiological tremors (17) as well as decreased performance (11). These decreases in psychomotor and cognitive performance can increase errors and subsequent accidents and decrease productivity.
Lastly, the long term effects of shift-work and jet-lag are largely unknown (10). Therefore, there may actually be more problems to consider such as hereditary illness and birth defects.
Some of the Solutions
Advances in the medical and psychological research have demonstrated that many of the problems associated with shift-work can be reduced by the appropriate application of guidelines. One document outlining the working conditions in 150 countries around the world demonstrated that Canada, as well as other countries, has no overarching labour legislation specifically protecting shift-workers (9). The shift-worker requires separate organizational and policy protections to be put in place since their working conditions are different from day workers; they must work when their biology dictates that they should be sleeping. The following guidelines could be used to effectively guide internal labour policies to help protect the health and well being of the shift-worker and reduce the risk of accidents.
1. After 50 years of age sleep is more deleteriously affected by shift-work (19 & 4). Shift-work should therefore be limited to those under 50 years of age. This would require strategic planning to ensure that day positions would be available to people reaching the age cut-off.
2. People classified as evening-types are better able to adjust to a rotating shift system (1). There are valid assessment tools to determine evening versus morning-types (6) and all employees being considered for shift-work should be appropriately screened to ensure biological compatibility.
3. Synchronizing time cues such as lighting, meal times, and socializing reduces the biological strain on shift-workers (8). The work environment should therefore be designed such that daytime light levels are maintained throughout the 24 hour period and break times for meals and socializing should occur at structured periods during the shift to ensure stimulation from contact with other people.
4. Napping as a countermeasure to the fatigue associated with shift-work must be taken with caution due to the pattern of post-nap performance decreases referred to as sleep inertia (14). Serious behavioural and cognitive performance decreases have been documented (5) that can last from 1 to 5 minutes (21) to 15 minutes (22). The positive benefits from naps, including increased performance and decreased errors, may be worthy of consideration for some industries (16).
5. Lastly, shift-work education programs have been effective at reducing some of the biological and organizational consequences of shift-work (12). The education programs should address the consequences of shift-work and how to detect warning signs of fatigue as well as provide practical tools for the shift-workers and their families.
It is somewhat hard to believe that all advanced societies do not have overarching legislation to protect their shift-workers. Research has demonstrated that improvements to the shift-worker’s health and well-being as well as benefits to the organization can be made with the appropriate guidelines directing internal policies.
Clinton Marquardt can help your shift-workers. Find out how by contacting him today!
References
(1) Anch, A. M., Browman, C. P., Mitler, M. M., & Walsh, J. K. (1988). Sleep: A scientific perspective. New Jersey: Prentice-Hall.
(2) Baddeley, A. D., & Hitch, G. (1974). Working memory. In The psychology of learning and motivation: Advances in research and theory (Vol. 8, pp. 47-89). New York: Academic Press.
(3) Coleman, R. M. (1989). Shiftwork scheduling for the 1990’s. Personnel, January.
(4) Dement, W. C., Seidel, W. F., Cohen, S. A., Bliwise, N. G., & Carskadon, M. A (1986). Sleep and wakefulness in aircrew before and after transoceanic flights. Aviation Space & Environmental Medicine, 57 (Suppl. 12), B14-B28).
(5) Dinges, D. F., Orne, F. C., Evans, F. J., & Orne, M. T. (1981). Performance after naps in sleep-conducive and alerting environments. In L. C. Johnson, D. I. Tepas, W. P. Colquhoun, & M. J. Colligan (eds.), Biological rhythms, sleep and shift work (pp. 539-553). New York: Spectrum Publishing.
(6) Folkard, S. (1980). Shiftwork and its effects on performance. In L. E. Scheving, & F. Halberg (Eds.), Proceedings of the NATO Advanced Study Institute on principles and applications of chronobiology to shifts in schedules with emphasis on man (pp. 293-306). The Netherlands: Sijthoff and Noordhoff.
(7) Folkard, S., Knauth, P., Monk, T. H., & Rutenfranz, J. (1976). The effect of memory load on the circadian variation in performance efficiency under a rapidly rotating shift system. Ergonomics, 19, 479-488.
(8) Fuller, C. A., Sulzman, F. M., & Moore-Ede, M. C. (1981). Shift work and the jet-lag syndrome: Conflicts between environmental and body time. In L. C. Johnson, D. I. Tepas, W. P. Colquhoun, & M. J. Colligan (eds.), Biological rhythms, sleep and shift work (pp. 241-256). New York: Spectrum Publishing.
(9) International Labour Organization (1995). Conditions of work digest: Working time around the world, vol. 14. Geneva: International Labour Office.
(10) Kales, A, & Kales, J. (1984). Evaluation and treatment of insomnia. New York: Oxford University Press.
(11) Klein, K. E., Bruner, H., Holtmann, H., Rehme, H., Stolze, J., Steinhoff, W. D., & Wegmann, H. M. (1970). Circadian rhythm of pilots’ efficiency and effects of multiple time zone travel. Aerospace Medicine, 41, 125-132.
(12) Kogi, K., & Thurman, J. E. (1993). Trends in approaches to night and shiftwork and new international standards. Ergonomics, 36(3), 3-13.
(13) Leuder, R. (1986). The ergonomics payoff: Designing the electronic office. Toronto: Holt, Rinehart and Winston.
(14) Lubin, A., Hord, D., Tracy, M. L., & Johnson, L. C. (1976). Effects of exercise, bedrest and napping on performance decrement during 40 hours. Psychophysiology, 13, 334-339.
(15) Michel-Briand, C., Chopard, J. L., Guiot, A., Paulmier, M., & Studer, G. (1981). The pathological consequences of shift work in retired workers. In A. Reinbrg, N. Vieux, & P. Andlaver, (Eds.), Night and shift work, biological and social aspects (pp. 399-407). New York: Pergamon Press.
(16) Naitoh, P. (1981). Circadian cycles and restorative power of naps. In L. C. Johnson, D. I. Tepas, W. P. Colquhoun, & M. J. Colligan (eds.), Biological rhythms, sleep and shift work (pp. 553-580). New York: Spectrum Publishing.
(17) Nicholson, T. (1973). Work, rest and safety in the air. New Scientist, 5, 404-407.
(18) Pati, A. K., Chandrawanshi, A., & Reinberg, A. (2001). Shift work: Consequences and management. Current Science, 81(1), 32-52.
(19) Preston, F. S. (1973). Further sleep problems in airline pilots on worldwide schedules. Aerospace Medicine, 44, 775-782.
(20) Scherrer, J. (1981). History of shift-work. In A Reinberg, N. Vieux, & P. Andlaver (Eds.), Night and shift work, biological and social aspects (pp. 1-10). New York: Pergamon Press.
(21) Webb, W. B., & Agnew, H. W. (1974). The effects of a chronic limitation of sleep length. Psychophysiology, 11, 265-274.
(22) Wilkinson, R. T., & Stretton, M. (1971). Performance after awakening at different times of night. Psychonomic Science, 23, 283-285.