Question

In a study to determine whether trans-fat consumption was associated with heart disease mortality, researchers studied the per capita consumption of trans-fats and the number of deaths per 100,000 population. They obtained this information for all 50 states in the US and created a plot showing the relationship between trans-fat consumption and heart disease mortality for each state. Use this information to answer the Questions 12 and 13.

1. What type of study design is this?
   1. Case
   2. Case-Series
   3. Ecological
   4. Cross-sectional

2. What is one advantage of this type of study?
   1. It is useful for etiological (root cause) studies
   2. It is useful for hypothesis generation
   3. It is relatively very expensive to conduct compared to other studies
   4. All of the above are advantages of this type of study.

3. What is one disadvantage of this type of study?
   1. It is expensive
   2. It is not etiological (root cause) studies
   3. It is relatively very expensive to conduct compared to other studies
   4. All of the above are disadvantages of this type of study.

Answer 1

Ans12:- c) ecological studies

13:- b) it is useful for hypothesis generation

14:- b) it is not etiological study (root cause)

See the above study is done on a population basis to compare population of two different groups which is generally done in ecological studies only all other studies individual based.

I.e unit of study for all other study is individual, not popuulation.

Ecological study we tried to to compare nutritional status for survey between two different populations based on secondary data collected by some other source like multinational companies and others.

Advantage of ecological study:-

It help in hypothesis formation and this study does not involved much of the research of fieldwork so it so it is very cost effective in comparison to other study.

Disadvantages:-

The main disadvantage of ecological study is ecological fallacy which state that the result of ecological study can't be applied on a particular individual of that population so so he does not help in finding the root cause.