Flashcards in Class 1 + 2: Type A personality - problems and solutions Deck (17)
What are Koch's 3 postulates? (What makes an agent causal?)
1. The agent is found in subjects with the disease (e.g. CHD patients have Type A personality)
2. Adding the agent to healthy patients causes them to develop the disease (e.g. Type A patients are more likely to develop CHD)
3. Remove it from patients and the disease goes away (e.g. Teach CHD patients to relax and their mortality risk goes down)
What is the psychosomatic approach? Why did it fail?
- Proposal that patients develop certain diseases because of specific psychological conflicts
Why it failed:
- No prospective studies (didn't have a healthy group of people to compare it with)
- Use of psychoanalytic interviews - data was subjective, and large-scale sample is not feasible/too expensive!
How do we test Koch's postulates to assert that Type A predicts CHD incidence?
Koch's #1: Establish that Type A personalities are common in CHD populations
Koch's #2: Follow a healthy population longitudinally, see if the people of Type A personality are more likely to develop CHD
What are some tools that can be used to assess Type A behavior?
1. Structured interview - clinical assessment (looks at answers and behaviors of patients)
2. Jenkins Activity Survey (JAS) -- questionnaire
What were the results of "The Pioneering Western Collaborative Group Study"?
(First study that established link between Type A personality and CHD incidence)
- Those with Type A personalities were more likely to develop a wide host of life-threatening illnesses (CHD, myocardial infarctions)
- Controlling for other risk factors like blood pressure, smoking and cholesterol, Type A personality STILL predicted CHD incidence!
What were the results of the MRFIT study?
- Used the standard interview method
- Found that when we use Type Bs as the reference group, the relative risks of Type As are NOT significant.
What did Jim Blumenthal find when he gave Cook-Medley Hostility questionnaire to coronary angiography patients he was doing Type A Structured Interviews on?
- Type As had more severe atherosclerosis
- Specifically, higher hostility scores were correlated with CAD severity
What were the findings of the "Interview-assessed Hostility and CAD in Healthy USAF Air Crew" study?
Higher hostility scores were associated with higher CAD incidence in non-smokers, but not in smokers.
- Because smoking in itself is a strong predictor of heart disease, and hostility doesn't affect it much more!
What were the findings of the "Interview-assessed Hostility, Anger-In and CAD in CHD Patients" study?
Those who had high tendency to direct anger inward had higher CAD (coronary artery disease) severity!
What were the findings of the "Hostility and Coronary Artery Calcification" study?
- High hostility scores at baseline were associated with: lower education level, higher alcohol use, current smoking, and a smaller fall in SBP over 5 years.
- Higher hostility scores associated with higher CA calcification. Controlling for potential confounders had little effect on these odds ratios.
- All genders and races are subject to the same risks - The effects of Ho scores to increase calcium scores were not different in men and women, nor in blacks and whites.
- Hostility scores predict mortality up until a score of 10, then levels off.
Is there a faster way to test Koch's Postulate #2 without finding a massive sample and conducting a longitudinal study?
Yes - use a study that has already been done
--> The Western Electric Study measured hostility scores
- This study showed similar results to findings in calcification study = mortality rises up until hostility score of 10, then levels off.
What did researchers find when they measured hostility scores of physicians who were 3rd year medical students, and followed up after 20-25 years?
Those who had hostility scores above 13 had a much higher chance of developing heart disease 20-25 years later.
- This was a group of healthy doctors!
What did researchers find when they measured hostility scores of lawyers in their 2nd year of law school, and followed up after 20-25 years?
Once again, higher hostility = higher mortality!
What did the study "Anger Proneness and CHD Risk" find? Specifically, were normotensives more or less likely than hypertensives to develop CHD?
CHD risk increased monotonically with increasing trait anger only among normotensive individuals, with HR of 2.69 (95% CI=1.48-4.90); no effects of anger were found among hypertensives.
*Similar to airforce crew finding, where the effect of high hostility scores only predicted higher CHD prevalence in non-smokers
- Negative traits such as anger and hostility have bigger health implications if you don't have other risk factors, such as smoking or hypertension!
What did researchers find when they measured hostility and mortality in CAD Patients Aged <61 Years?
Even in patients who already had heart disease, hostility still predicted greater mortality rates!
How does hostility affect other aspects of a person's life?
Affects quality of a career -
(Rigidity, poor relationships, poor self-control, defensiveness, poor social skills)