Shiftwork, burnout and sleep disorders

Technological advancements in the 21st century have resulted in more 24-hour work schedules compared with previous generations and are associated with less sleep time and a perception of increasing sleep difficulties. Extended work periods outside the traditional work hours of '8 to 6' are common. It is now estimated that 15-20% of the work force in industrialised countries are shiftworkers while recent Australian figures suggest around 9.3% of the population are shiftworkers. However, many younger employees work on a part-time or casual basis, and are not necessarily incorporated into the Australian Bureau of Statistics figures.

Many individuals experience an extended working week of 41 to 50 hours, which applies not only to employees but also for managers and business owners. The combination of extended work hours and working around the clock (circadian rhythm imbalance) is associated with increasing fatigue, sleep difficulties (in particular, insomnia) and in extreme conditions results in a clinical condition called shiftwork sleep disorder. The increasing availability of electronic communications has further clouded the boundaries between work and leisure. Working from home or taking work home further extends the work period, decreases leisure time and is associated with stress and has negative health implications.

Working at night further compromises performance at work with 75% of night shiftworkers reporting sleepiness on every shift, and generally losing five to seven hours of sleep per week compared with daytime shiftworkers. It is not unusual for shiftworkers to fall asleep between 0200 hours and 0400 hours (up to 1/5th) and 32% of workers who fell asleep achieved some deep sleep, which illustrates their degree of sleep deprivation. Shiftworkers constantly experience a 'jet lag effect', as they remain on a diurnal pattern, even though they are working at night and trying to sleep during the daytime. The maintenance of the diurnal pattern in shiftworkers is related to wanting to be on the same time zone as their families on 'days off'. These workers are constantly dealing with increasing sleepiness and decreasing alertness on a nightly basis while they are at work.

Health surveys (The National Sleep Foundation Report, 1997) indicate that 36 million people in the US complain that sleep loss reduces work performance. Specific consequences include a perceived loss of concentration; difficulties with decision making, problem solving; a lowered ability to listen and relate to co-workers. The resulting loss in productivity is estimated in the United States as being US$18 billion. Occupational accidents, absenteeism, substance abuse, a vulnerability to psycho-physiological disorders and fatigue-related motor vehicle accidents, particularly on the journey to work if starting before 6 am or going home, are common associated consequences of shiftwork.

Previous research has shown that burnout is caused by increased workload, and work-related stress, which in turn appears to be the trigger for stress-induced sleep disturbance and is an ongoing negative consequence of shiftwork. Our present work practice leaves the average worker vulnerable to an ongoing cycle of work, work stress, poor sleep and burnout.

What is burnout?

Job burnout has been described as a 'psychological syndrome in response to chronic interpersonal stressors on the job'. The most common features of burnout are emotional exhaustion, depersonalisation and detachment from the job, feelings of reduced personal achievement and incompetence at work, and appears to be more prevalent in workers who are involved in 'people work'.

Predisposing factors for burnout include personality characteristics such as being more anxious, being depressed, experiencing sleep disturbance and poor health. Emotional exhaustion appears to be the core component of burnout, where the individual's energy resources are depleted emotionally, mentally and physically. Burnout is also thought to have symptoms similar to chronic fatigue syndrome (CFS), depression and vital exhaustion.

Although the emotional component of burnout is often perceived as having the most negative impact on workers, research has shown there are specific detrimental physiological correlations of burnout. In a recent Swedish study of 43 women with high scores and 20 women with low scores on the Shirom-Melamed Burnout questionnaire, their data was compared on a range of subjective and physiological factors. Women with the high scores on the burnout questionnaire reported more job strain as in less control in the work setting, less social/work support, more anxiety, depression, exhaustion and sleep difficulties compared with the women who had lower burnout questionnaire scores. In addition, changes in some specific cytokines (chemicals that the immune system uses for communication) were found to be elevated in individuals with high burnout scores. Other earlier research found increased serum lipids predicted emotional burnout in women while for men total cholesterol level changes predicted burnout.

There also appears to be some differences in reported levels of burnout between countries and particularly between North America and Europe with European workers reporting lower rates of exhaustion and cynicism compared with their North American counterparts. The reason for these cultural differences in burnout are unclear at present, but it has been surmised that 'burnout' may be a more socially accepted term in North America, and a higher achievement orientation at work is required, which in turn increases stress. Another explanation is differences in actual working conditions between the two continents.

How do we deal with burnout?

Most of the so-called treatment of intervention in burnout situations has been at an individual level, where the worker has been removed from the job or transferred to another section. Yet this approach is ignoring the triggers for burnout, which include the situational and organisational factors in the workplace environment.

Of key importance is educational intervention, which helps individuals to manage their current workplace environment by feeling part of a team. This strategy is achievable, however interpersonal relationships are not as easy because most workers are hired on the basis of their work skills and not their personality. Organisational change can also occur through intervention strategies in a number of areas such as teaching workers to deal with work overload, how to cut back on work and relaxation strategies. When someone is stressed at work and sleep deprived they are also more likely to experience sleep difficulties.

Insomnia

Stress is a common cause of primary insomnia. Insomnia is a distressing difficulty in initiating sleep, maintaining sleep or a combination of these symptoms, which increases with age when there are other medical and psychiatric conditions present.

Many shiftworkers are able to go to sleep due to the effects of sleep deprivation but have great difficulty maintaining sleep due to increased awakenings from an increasing core body temperature, which normally occurs during the daytime (circadian rhythm disruption), disturbance from increasing light and noise factors and having to curb sleep due to family and social responsibilities. An associated pattern of poor sleep, increasing fatigue, increasing anxiety about sleep and concerns about being alert at night or on the road becomes the prevalent pattern for working and dealing with non restorative sleep.

Previous Australian studies have shown that 16.2% of the population reported mild or occasional sleeplessness while 9.4% reported moderate to severe sleeplessness. More recently, a randomised study of individuals from the NSW electoral roll found an insomnia prevalence rate of 32% where insomnia symptoms were reported on a casual basis (unpublished MAA report 2004). 12% of this population were full-time shiftworkers with 21.4% working in part-time employment. Again, there is this association between shiftwork, sleep disturbance and burnout.

Shiftwork Sleep Disorder (SWSD)

SWSD is an extreme example of sleep disruption as a consequence of shiftwork. The actual prevalence of this disorder is unknown but is thought to affect between 2-5% of the shiftworking population. Symptoms include insomnia symptoms, excessive sleepiness that occurs on a transient basis in relation to work schedules and inability to maintain a normal sleep duration after a night shift when trying to sleep in the morning, despite having no other factors that would interrupt sleep.

Other factors include excessive sleepiness at work, an overwhelming need to nap at work and impaired function and alertness at work. Predisposing factors for SWSD include being a morning person or 'fowl', being older and not being able to adapt to shifts or changes in sleep/wake patterns.

Obstructive Sleep Apnoea (OSA)

Even when sleep length is adequate, sleep quality may still be disturbed by disorders by repeated awakenings such as occur in obstructive sleep apnoea (OSA).

Sleep apnoea affects up to 25% of the middle-aged male population (24-26) and leads to impaired cognitive performance, sleepiness during work and while driving and most likely long-term cardiovascular and immune function complications. These sleep problems are further exacerbated by shiftwork or jet lag, where the body's clock time (circadian rhythm) is out of sync with the clock time in the environment.

Males with sleep apnoea have a five times greater likelihood of having multiple car accidents in the previous five years. Many shiftworkers have second or third jobs, further exacerbating the problem of sleepiness, reduced productivity, increasing costs and increased accident risk rates at work, on the road and at home. Increasing work time produces a logarithmically increasing work accident rate after about 10 hours continuous work time on shift. Older shiftworkers are less likely to have a healthy diet, are more likely to be overweight and not be in a regular exercise program.

Sleep disorders

Other sleep disorders are present in any population and include movement disorders such as Restless Legs Syndrome (RLS), Periodic Limb Movement (PLM) and disorders of excessive daytime sleepiness such as narcolepsy.

In summation, poor sleep is a predisposing factor in burnout while shiftwork is associated with poor sleep, poor diet, insufficient exercise, sleep disorders and burnout. Of importance is how we learn to manage these factors to prevent an escalating circle and cycle of sleep disturbance, poor performance, decreasing alertness and increasing accident risk rates in a society where shiftwork may soon become the more normal pattern of working and living.