Cohort Study and Other Observational Studies

[hedleypanama]

This is a common misconception: the timing of the disease has NOTHING TO DO with the design. The actual theory states that cohort study is an specific and homogeneous population which all its members differs (at least theoretically) in at least 2 groups according to their exposure status (so we investigate the proportion of cases in each group).

A case control study is a representation of a cohort where all cases are identified and a sample of non-cases are taken from the original cohort.

[hedleypanama]

@hedleypanama I was taught in the same way, when I was student. I am a PhD student in epidemiology, and I learned the correct way.

I recommend you to read "Epidemiology: An Introduction", in order to clarify such terms.

Additionally, that "old" definition, make invalid "historic cohorts" and "nested case-control" designs which are supported by this new framework proposed by modern epidemiologists like Rothman.

I remember "ecological" studies and descriptive=cross-sectional ones.

[hedleypanama]

@hedleypanama Another thing: case-control studies measure association using odds ratios and cohort can use odds ratios and hazard ratios. Cohort never show odds ratios (although they can be calculated) that makes no sense in presence of hazard ratios.

[kabulsh]

Great videos :) Thank you - keep it up

[mysoukouss]

These are the best, detailed high level discussions by a person who knows what he is saying and how to simplify tough stuff. Thanks for all your lectures doc.

Please keep on sharing your great knowledge. I love your pharmacology, anatomy and physiology , stats, research and all your videos.

[TJLahori]

Thanks. it was useful.

[Supergirl4eva]

what was he saying at the end it cut him off :(

[herizenfall]

Simple, clear. Thank you



[fushichuu]

o_O

[hertot]

omg!!! i in love with you!!!!

[Thetrollmaster2000]

... Like my indian Lecturer... i cant understand a word u are saying

[faranv]

Thank you! This was very helpful.