Question

In: Statistics and Probability

A recently published analysis examined 10 studies that measured optimism and pessimism by asking participants about...

A recently published analysis examined 10 studies that measured optimism and pessimism by asking participants about their level of agreement with statements like “In uncertain times, I

usually expect the best,” or “I rarely expect good things to happen to me”. Optimistic people tend to expect that they will encounter favorable outcomes, whereas less optimistic people tend

to expect that they will encounter unfavorable outcomes.

These studies also measured other variables on participants, including factors related to heart disease. The analysis found that compared with pessimists, people with the most optimistic outlook had a 35% lower risk for cardiovascular events (e.g., heart attacks). The studies, on average,observed people over a 14-year period and compared the rate of cardiovascular events between those classified as optimists versus pessimists.

a) Briefly describe a plausible study design that has the potential to demonstrate the effect of thinking positively on cardiovascular health.

b) Suppose someone who is very optimistic reads about the analysis and concludes that the findings suggest he has a 35% lower risk for cardiovascular events than his friend who is

extremely pessimistic. Explain why this is not necessarily the case.

Solutions

Expert Solution

a) In this study design researchers are trying to find the relation between cardio-vascular disease for two different sets of people optimistic and pessimistic So this is an cause and effect model and can be classified as CRD (Completely Randomised Design) where we are looking at the effect of Factors Optimistic and Pessimistic.

We can analyse the same with ANOVA and find the effect betwwn 2 factors.

However, we may be ignoring certain other factors which may cause cardio-vascular disease, like age of the person, pre-existing medical condition, general lifestyle, medical management followed and other related factors which may lead to cardio vascular disease.

So the analysis may not reveal the true picture unless and until the sample comes from homogeneous conditions apart from being optimistic or pessimistic

b) As explained in last part, we are ignoring his current medical condition and other factors which may lead to cardio-vascular disease. From the study we can only say that optimistic people has a fair advantage than pessimistic person only if they are having same kind of lifestyle and medical condition,


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