Sawmill finishers and repetitive work

Johansson et al (1978) studied a small group of workers in a large sawmill.  Their job was ‘finishers’, i.e. they were the final link on a conveyer belt system.  The rate at which they worked determined the output of the mill so their job was very responsible. 

Sources of stress included: responsibility for the mill’s output, responsibility for the pay of other employees (since pay was linked to productivity), working in isolation, so didn’t have others to share problems with, little control (since they worked on a conveyor belt), highly skilled but repetitive work.

The researchers’ measured their stress hormones (adrenaline and noradrenaline) and patterns of illness. 

Findings:  They had much higher levels of absenteeism due to illness and higher levels of adrenaline in their urine, but only on work days. 

Conclusion:  The researchers recommended that the finishers should move to a salary structure (i.e. pay not based upon output) and should be allowed to rotate jobs with other workers.

Effort-reward imbalance

Ever got that feeling that all your hard work isn’t being recognised or that you don’t feel you’re getting the rewards that you deserve?

Kivimaki et al (2002) published the results of a 25 year study of 812 workers.  Those with an effort-reward imbalance were twice as likely to suffer from cardiovascular disorders such as CHD than those who felt that they were being recognised for their efforts.

Smith et al (2005) got similar findings and put the results down to increased anger caused by the feelings of injustice.  This could be compared to Friedman and Rosenman’s findings of hostility and anger being related to CHD with type A behaviour.

Few overall points to conclude this section:

Changing places

The modern workplace is a rapidly changing and evolving environment due largely to advances in technology which have created different working practices such as virtual environments, conferencing etc.  As a result, research becomes outdated very quickly.

Individual differences

Again we come back to the transactional model of stress.  This emphasises the importance of individual differences, especially In our perception of stress and our ability to cope.  One person’s stress is the thrill seeker’s pleasure.  We all react differently and have different perceptions of our ability to cope.  This tends not to be considered in the above studies. 

This brings us nicely to the next section.

The data is also largely correlational with all manner of variables, such as life outside of work, not being considered.  It is therefore impossible to be certain that job strain per se is the cause of the increased levels of CHD.

Very recent research by Dr Michelle Albert (Nov 2010)

Over 17,000 women in Boston, USA were studied over a period of ten years.  Those in high strain occupations had a 40% greater risk of cardiovascular disorders and 88% increased risk of suffering a heart attack.  She also reported that job insecurity and the worry of unemployment increases the chances of CHD and hypertension.

Ellen Mason of the British Heart Foundation added that the precise link between stress and CHD is still unclear, but there is growing evidence that high stress weakens the artery walls. 

Occupational stress and CHD

Evidence for a link between stress and coronary heart disease (CHD)

Cobb and Rose (1973) analysed medical records and found that air traffic controllers (considered to be an extremely stressful occupation) were at significantly greater risk of developing hypertension (long term high blood pressure).  In fact there was a positive correlation with those working in airports with greatest airplane activity suffering the highest levels of hypertension.

However, hypertension can be caused by a variety of factors such as obesity, too much salt, lack of exercise and genetic inheritance as well as social factors such as stress and anxiety.  Therefore we can’t rule out other possible causes in ATCs and other high stress occupations.  Perhaps people in such jobs tend to leave unhealthier lives and as a result of lifestyle put themselves at greater risk.

Job strain and CHD

Karasek et al (1982) followed 900 workers for ten years.  A combination of job titles and self-report questionnaires were used to measure job demand and control. 

High job strain was considered to be the result of high demand jobs but with low control.

Those workers with high job strain were 1 ½ times more likely to develop CHD during the study.

Johnson and Hall (1988) studied 14,000 Swedish workers

They measured:

1.   Work control: the variety of tasks, control of holidays, ability to plan work etc

2.   Social support: chances to talk to others, number of out of work get togethers etc.

3.   Psychological demands of the jobs such as how hectic and how demanding

4.   Their cardiovascular health

Findings

Similar to those of Karasek: those involved in high demand/low control jobs were most likely to develop cardiovascular problems.  Fewer chances for social contact seemed to be a particular risk factor.

More recent versions of the job strain model now include social support as a major factor.

However

Both of the above studies rely heavily on self-report techniques making them less reliable.  A persons perception of their workload may not be entirely accurate or unbiased!