DrVirgo
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Whats the difference between Cohort and Longitudinal Study?
-They BOTH go forward in time, so how do you differentiate between them?
Can anyone give any examples of the two?
Thanks.
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| DrVirgo
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Ok, here is the answer:
In Cohort studies, subjects are asembled on the basis of some common experience (such as attendinding medical school) and are then monitored for a specified amount of time at regular intervals (e.g., taking Step 1, 2, and 3) until they develop the outcome of interest (they become practicing physicians) or the follow up time ends. The cohort stydy minimizes many of the biases evident in case-control designs and is the definitive observational clinical study. Cohort allows researchers to compute a relative risk.
Longitudinal Studies identify individual subjects and follow them over a given period of time. For example, the study of cholesterol-lowering drugs on cardiovascular events requires that the same subject is observed over a significant period of time.
If anyone has any more examples of these kind of studies please post them.
Thank.
___________________
Our greatest glory is not in never falling, but in rising every time we fall.
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| gafat
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Posts: 11
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I think Drvirgo already gave a good discription of the difference b/n the two. To add more example on the topic,
In cohort study, you catagorize your study population as " Exposed" and " not exposed" at the start of the study and follow them for an outcome. For example you can follow smokers and non smokers for a period of time to check which group is more pron to a certain outcome. This is tipical cohort.
In longitudinal study , what is important is the time in which subjects are follwed. A good example of longitudinal study ( whic is not cohort ) will be a child survival study. In this case you follow all children for a period of one or 2 or 3 or what ever years with out prior assignment to a certain risk factor check which ones servive and which ones not.
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