Question

1. 6. Explain ecologic fallacy and its importance

1. 7.A study to test the hypothesis that volcanic dust causes silicosis is to be tested by comparing the population of an island very close to a volcanic eruption with the population of an island not so exposed. After 5 and 10 years the incidence of silicosis will be measured and compared in both populations. This study is:
2. 1. a. Cross sectional
   2. b. Case-control
   3. c. Prospective cohort
   4. d. Randomized controlled

Answer 1

6)Ecological fallacy means the results of the ecological study are not applicable to the individuals.The results of other kinds of studies are applicable to the individuals, but not the ecological study.

Example-- If a certain risk factor increases the risk of breast carcinoma by 20% in a population, it doesn't indicate that for a particular person, the risk is increased by 20%.

Importance is that ecological studies are used in population studies and should not be applied to the individuals.

7)Two groups of people are selected and then followed for 5 and 10 years .So this is an example of prospective cohort study.The people are followed into the future ,so prospective.