Study Designs part2

?Ecological Studies: based on studying of a group of people not individual as in previous studies.
?Correlation data represent average exposure level rather than individual level so we do not have each person information
?Ecological studies can generate a hypothesis and need further confirmation , it provides just initial clues to causation
?Example : as meat consumption in different countries increases prevalence of ca colon increases , Cigarette smoking increases ca lung prevalence increases as well
Advantages of Correlational Study
1.They describe the disease in the entire population in relation to the factor of interest.
2.They use the correlation coefficient (r) to measure the association between the two variables of interest.
3.They are easy to do, inexpensive and can be conducted quickly.
4.They represent the first step in searching for exposure-disease relationship (generate hypothesis)
5.They use available data (administrative or other aggregate data).
?Ecological Studies: based on studying of a group of people not individual as in previous studies.
?Correlation data represent average exposure level rather than individual level so we do not have each person information
?Ecological studies can generate a hypothesis and need further confirmation , it provides just initial clues to causation
?Example : as meat consumption in different countries increases prevalence of ca colon increases , Cigarette smoking increases ca lung prevalence increases as well
Advantages of Correlational Study
1.They describe the disease in the entire population in relation to the factor of interest.
2.They use the correlation coefficient (r) to measure the association between the two variables of interest.
3.They are easy to do, inexpensive and can be conducted quickly.
4.They represent the first step in searching for exposure-disease relationship (generate hypothesis)
5.They use available data (administrative or other aggregate data).