WJEC PY2 Rahe et al

Through the 1950s many studies explored a relationship between stress and health. Han's Selye's research in the 1950's suggested a causal link between psychological stress and physical illness. Selye found that rats gave the same response to stressful events, regardless of the stressor used - alarm reaction, resistance and exhausation.

Holmes and his partner Hawkins worked in a TB sanatorium and found that infectious illness was more common among poor people. The emotional effects of poverty increased their vulnerability to physical illness.

Rosenman and Friedman (1958) found a link between stress and coronary heart disease.

• Their work was based on an observation of patients with heart conditions in a waiting room.
• Unlike typical patients, these patients were unable to relax comfortably in chairs, tended to leap out of their sears, can't sit still and wait.
• Rosenham and Friedman concluded that such individuals had a type A personality and were more likely to experience high levels of stress and were more likely to suffer ill health related to heart disease.

In the  1960s this work was further developed by Dr Richard Rahe working with Dr Thomas Holmes. They realised that some kind of measuring tool was needed in order to measure stress related life changes. To do this they analysed case histories of more than 5000 patients, producing a list of 43 critical life changes. The stressfulness of an event was established by asking 400 people of different ages,gener and education to score each life changing event.

The participants were asked to provide a numerical figure for each life changing event, marriage having a baseline number of 500. These numerical figures were called life changing units - LCU's.

If an event would be more stressful than marriage then the score would be higher. The 43 events were used to construct the 'Schedule of Recent Experience (SRE) (Rahe et al 1964) and later the Social Adjustment Rating Scale (SRRS)

This data gave the researchers the means of collecting quantifiable data to investiagate how stressful life changes can be. However it was seen as unethical to expose participants to stressful life events just to measure how stressful they would be, therefore retrospective studies were conducted (studies involving people who had been ill)

Aims

Rahe, Mahan & Arthur, using prospective methods, aimed to investigate if there is a relationship between the pre-deployment life events score (SRE) and the number of reported illnesses during deployment.

The study consisted of

• 2463 Navy enlisted men
• 125 Navy officers
• 96 Marine enlisted personnel stationed aboard three US Navy cruisers.
• Two were aircraft carriers involved in military operations off the coast of Vietnam, the other aircraft carrier was based in the Mediterranean.
• The mean age across the three cruisers was 22.3 years from a range of backfrounds in terms of education, rank and maritime experience (10% were lost by being transferred to other ships)
• The sample represented between 90 and 97% of each ship's crew.

1. Participants were asked to fill in the military version of the SRE, a questionnaire documenting significant changes in a person's life, relating to personal, family, community, social, religious, economic, occupational, resedential and health experiences. Each sailor completed the SRE every six months over a period of two years prior to 6 to 8 months deployment.

A total LCU score for each participant was calculated for each of these participants

2. Each stressful experience recorded on the SRE is assigned a life change unit (LCU) a weighting that indicates the severity of that source of stress. The allocation of weightings had been previously established using a group of American civilians and had found to be consistent when compared to other samples.

3. As a ship returned from the overseas assignments, a research physician went aboard and reviewed all of the sailors' health records. Each ship has a medical facility where all records were kept. Any illnesses even minor ones were recorded by the ship's medical facility. 

4.Neither the participants nor the medical departments on the ships were aware of the search aims of this project (double blind technique)

A significant positive correlation coefficient of 0.118 (p<0.01) was found between the LCU totals for the six months prior to deployment and illness.

 A positive linear relationship between the number or intensity of life changes recorded by a subject over a 2 year period and his likelihood of developing subsequent major health change was evident.

Further analysis revealed that their Total LCU (TLCU) for the 6 month period immediately prior to their 6 – 8 month deployment demonstrated a significant relationship with the illness criteria. This was most apparent in cruiser 1 and 3 and in the married enlisted men category compared to young single sailors.

Furthermore, sailors that fell into the low TLCU groups (labeled decile 1 & 2) represented a definite low illness group, conversely sailors with a high TLCU score (labeled decile 9 &10) represented a high illness group.

Mean number and standard deviation of cruise period illness, per decile, for the three cruisers combined.

The results of this prospective study support the notion of a linear relationship between participants TLCU and illness rate. It is important to note that the illnesses experienced by the men were generally minor in degree and their pre-deployment life changes were often few and of low significance, however this does not detract from the impressive findings that are consistent with other prospective/retrospective studies.

Correlational analysis: argued that other research methods such as lab experiments would have been inappropriate due to ethical issues involved e.g. to make people stressed in controlled conditions is not ethically acceptable. Weakness it only tells us that there is a relationship between life events and illness and cannot conclude that one causes the other.

Sample: large, strength, weakness because only consists of American males and represented those that work in the military, women may respond to stress differently to men.

Double blind: means neither the participants or the doctors giving the medical reports knew the aim of the study, strength prevented demand characteristics, weakness because deception.

Ecological validity: natural setting, strength, natural behaviour.

Hans Selye supported this research as he found a link between the stressful events administered ti rats and their rates of illnesses.

Dr Thomas Holmes and Norman Hawkins, they studied the effects of poverty on illness by assessing a TB sanatorium and observed that illness was more common against poor people. They did not cite that poverty was the cause per say but rather the emotiobal effects of poverty on people. These emotional effects of poverty on people. These emotional effects strongly enhanced the chances of illness. These findings support the findings of Rahe's study because they cited emotional effects as a link to illness not poverty but rather other life changing events.

—Palesh et al. (2007) Breast cancer relapse more likely if more stressful life events have been experienced.

—Villalva et al. (2002) —Sample: 236 older patients (mean age 64yrs) suffering from hypertension. —Method: Measure blood pressure at baseline and follow-up. Complete SRRS at follow-up. —Findings: Participants with a LCU over 150 showed a significant increase in blood pressure and heart rate. —Criticism: Sample with existing health problems. —Gupta and Gupta (2004) Stressful life events significantly related to skin disorders in healthy people.