Temporal Conditions Of Work Environments

Question 1

Condition 1

Answer 1

Shiftwork (Pheasant, 1991)

1. Temporal conditions refer to the time conditions under which people work.
   > Many people work at night in a variety of organisations; manufacturing sometimes continues for 24 hours, health care needs to be available 24 hours a day, and leisure and retail services are becoming increasingly available 24 hours a day.
   > This means that increasing numbers of people work ‘shifts’, a term used to describe any working pattern that does not involve the same work pattern every week.
2. To maintain 24 hour service, many organisations run a rotation of three shifts per day.
   > Day shift: 6am - 2pm
   > Afternoon (or twilight) shift: 2pm - 10pm
   > Night shift: 10pm - 6am
3. It is important to manage shifts so that any negative effects can be reduced.
4. Pheasant identifies two main approaches to the organisation of shift working:
   A. Rapid rotation shifts theory
   > Frequent shift changes that workers have to follow.
   > metropolutan rotas are where workers work two day shifts, then two afternoon shifts and then two night shifts. They then have two days off before the shift pattern starts all over again.
   > Note that this is a total of eight days per rotation so that the weekly pattern shifts a day ahead each week.
   > A continental rota is where workers complete two day shifts, two twilight shifts, three night shifts, then two days off work, two day shifts, three twilight shifts, two night shits, and then three days off work. After this, the cycle begins again.
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   B. Slow rotation shifts theory
   > Changes are infrequent changes.
   > For example, working day shifts for several weeks and then night shifts for several weeks.
   > It is suggested that this kind of slow rotation can allow circadian rhythms to adapt to one shift without being forced to change too rapidly and cause health problems.

Question 2

Condition 2

Answer 2

The effects of shift work on health (Knutsson, 2003)

1. In Knutsson’s 2003 review of the effects of shift work, he brings together evidence on the relationship between working at night or on a shift work pattern and specific serious medical disorders.
2. He begins by noting that there is no specific evidence that suggests that shift work actually affects longevity.
   » Two studies are mentioned that have directly compared mortality rates between day workers and shift workers, one conducted in the UK and one conducted in Denmark.
   » The UK reported no significant difference and the Danish study reported a very tiny increase in relative death risk for shift workers.
3. Knutsson moves on to examine specific disorders and conditions:
   A. Gastrointestinal disease
   > Significantly common in shift workers than in day workers.
   > Most commonly constipation and diarrhoea experienced when working night shifts.
   > Some evidence shows that peptic ulcer are more common in those who regularly work shifts, including taxi and truck drivers, factory workers, printers and night watchmen.
   > The risk of duodenal ulcers is also reported to be doubled in shift workers.
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   B. Cardiovascular disease
   > Well known that working conditions can contribute to the risk of cardiovascular disease.
   > This includes physical factors such as chemicals, noise and vibrations as well as psycho-social factors such as stress and the organisation of work schedules.
   > Studies conducted in a range of different countries support the relationship between shift work and cardiovascular disease.
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   C. Cancer
   > Some research has revealed an increased risk of breast cancer in women who work night shifts.
   > These studies have been conducted with nurses, flight attendants and radio and telegraph operators.
   > However, increased exposure to other carcinogens in these occupations could not be controlled for.
   > There has been some discussion about the role of low levels of melatonin but there is no conclusive evidence for the risk of cancer being increased by shift work.
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   D. Diabetes and other metabolic disturbances
   > Concentrations of certain substances in the body, including potassium, uric acid, glucose and cholesterol are higher during night work which may be related to increased metabolic disturbances.
   > Studies of weight and body mass index (BMI) have tended to be inconclusive, although some have shown higher BMIs in those working shift work.
   > However, there is evidence to support the increased chances of developing diabetes if you work shifts.
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   E. Pregnancy
   > Studies show relationships between shift work and low birth weight as well as shift work and premature birth.
   > One paper has reported an increased risk of miscarriage among shift workers.
   > Knutsson argues that this evidence is strong and that pregnant women would be well advised to avoid shift work.
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   F. Exacerbation of existing disorders
   > Many normal biological processes follow a circadian rhythm and this can be interrupted or interfered with by shift work.
   > This means that taking medicines is more complex when working shifts.
   > Even taking the same dose at the same time can cause different effects due to the differences in the internal body clock.
   > Sleep deprivation can also affect existing disorders such as the frequency of seizures experienced by epileptics and the frequency of asthma attacks.

Question 3

Condition 3

Answer 3

Shift work and accidents (Gold et al., 1992)

1. Gold et al. conducted a survey of Massachusetts nurses which asked about shift work, sleep and accidents.
   A. Background
   > Used a self-administered questionnaire and was handed out to 878 registered nurses between June and September 1986.
   > They were asked whether they worked variable shifts or whether they always worked the same shift.
   > The nurse was asked to give information relating to the current week, the previous two weeks and the following week on the number of day, evening or night shifts worked.
   > They were also askedto record their sleep and wake times for all shifts and for days off.
   > Questionnaire also asked about:
   » Quality of sleep
   » Use of alcohol
   » use of presciption or non-prescription medication
   » Sleeping aids
   » Times they had ‘nodded off’ at work in the past week
   » Times they had ‘nodded off’ whie driving to and from work in the past year
   » Accidents, errors and ‘near-miss’ accidents in the past year: this included driving accidents, medication errors, job procedural errors and work related personal injuries that could be attributed to sleepiness
   > Of the 878 questionnaires given out, 687 were returned.
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   B. Participants
   > They were divided into groups dependent on their work practices.
   » Day and evening shift work was group together as the shift from day to evening work has not been shown to disrupt circadian rhythms.
   » Night shifts only and ‘rotators’; those who changed shift patterns frequently.
   > Mean age of the sample was 33.9 years.
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   C. Results
   > Rotators and night shift workers reported fewer hours of sleep than day/evening workers.
   > Anchor sleep
   » The researchers used a concept of ‘anchor sleep’ which defined as having four or more hours sleeping during the same clock hours every night.
   » 92% of the day/evening nurses obtained regular anchor sleep but only 6.3% of the night nurses and none of the rotators obtained anchor sleep regularly throughout the month.
   » Anchor sleep disruption was experienced by 49% of the day/evening workers, 2.9% of the night nurses and 94% of the rotators.
   > Poor quality sleep
   » Night nurses were 1.8 times more likely to report poor quality sleep than the day/evening workers, and rotators were 2.8 times more likely to report poor quality sleep than the day/evening workers.
   » Night nurses and rotators were twice as likely to use medications to help them sleep.
   > Nodding off
   » Nodding off on the night shift occurred at least once a week in 35% of rotators, 32% of night nurses, and 20% of day/evening workers who worked the occasional night shift.
   » In contrast, only 2.7% of day/evening nurses and 2.8% of rotators reported any incidences of nodding off on day or evening shifts.
   » When compared to day/evening nurses, rotators were 3.9 times as likely and night nurses 3.6 times as likely to nod off while driving to and from work in the previous year.
   > Accidents
   » Although length of time working at the hospital, age and use of alcohol were factors taken into account, rotators reported twice as many accidents as day/evening nurses.
   > The results are consistent with laboratory demonstrations of the effects of sleep deprivation and the disruption of circadian rhythms, particularly in the sense of increased cognitive errors.
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   D. Conclusion
   > The application of circadian principles to the design of work schedules may produce improved health and safety for nurses and patients.

Question 4

Evaluation

Answer 4

1. Nature vs Nurture explanations
   > Shift work may interfere with the natural functioning of the body and this is likely to explain the many negative effects.
   > We have a natural circadian (daily) rhythm and working constantly changing shifts may disrupt this.
2. Self-report
   > Those considered by Gold et al. rely heavily on self-reports.
3. Application in everyday life
   > By identifying the risks that shift working may pose, not only are individuals able to make informed decisions about their own working practices, but employers are able to establish procedures designed to minimise these risks.
4. Correlational
   > The effects identified by Knutsson are correlational.
   > A correlation shows a relationship between something; for example a relationship between working shifts and an increased chance of gastrointestinal disorders.
   > However, it does not show that working shifts cause an increase in gastrointestinal disorders even though it might seem to make sense to interpret the results in this way.
   > To show a causal relationship, we would need to have conducted an experiment.
   » We would need to have carefully controlled for all possible extraneous variables and then randomly allocated similar participants to both the experimental and the control group.
   » The experimental group then work changing shifts for a period of time whilst the control group would work normal day shifts.
   » If, at the end of the study, there was a significant difference in the incidence of gastrointestinal disorders, and we could show that we had controlled for all possible extraneous variables, we could conclude that working shifts cause gastrointestinal disorders.
   > However, this type of research would raise many ethical issues and would be unlikely to be conducted.
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   > It is also difficult to draw causal conclusions from the research by Gold, although this can be described as quasi-experimental as he was able to compare two naturally occurring groups, thus creating independent variable.
   > However, he was not able to randomly allocate participants to these different groups meaning that there may be many differences between them that might explain the results he found.
   > However, the research findings are supported by laboratory experiments into short-term sleep deprivation and cognitive errors.
   > There may be reporting biases in this study and a longitudinal study to track accidents and errors, and to correlate these with shift work patterns might be more effective.