Using Odds ratio in case control studies

[olarcharles]

I am in my first year and my first course unit is Epidemiology, I am benefiting from this lecture, I am still grasping the whole concept. Thank you so much

[phanicemaroria]

well elaborated hv been given an assignment have used all your example to work it out
thanks alot

[nurhafizsahzaimey]

hi! I just wanna thank you for this video. I just finished my epidemiology paper today and I couldn't do it if its not because of you. thank you so much for your videos. you're the real MVP. =)

[FRACP]

This is excellent! Other videos I found simply went through the 'cross-method' without explaining the proper way first (which I figured out myself) but I'm glad you're video confirmed it!

[evabudinska]

Hi Elizabeth, thanks for this video. I was wondering which of the two types of interpretations of OR is most common. The second one is to calculate OR as (a/b) / (c/d) which gives the same result: (a*d)/(c*b), however, it is interpreted as odds ratio between odds of event in the exposed group vs odds of event in the non-exposed group.

[Daniel-rkqz]

+Elizabeth Lynch So... can we say that we only use case-controls when a disease (outcome) is rare and so we want to find the risk factors? Whereas otherwise, if the disease is prevalent, then it is a BETTER option to use a cohort study? And does this also mean that our ULTIMATE GOAL is to find a good estimation for a relative risk in order to determine how it affects the person's pre-test probability?

Thank you! this is probably the most challenging part of med school haha.

[shinomri]

Pobably the best video to illustrate OR I've seen. For visualisation purposes I think showing why OR approaches RR with an example might be a good idea, since it's not hard to demonstrate, but seems like a neubulous statement often mentioned otherwise...

[aishasultan]

Thank you so much, such a helpful and simple video.

[somebody]

Hello do you have a vid on how to calculate unmatched ratio? Ty.

[Neunhoffer]

Hi. I am trying to figure out how the cdc arrived at 2.34 times odds for their covid study in kentucky. I cant figure out how this is calculated. Can you help?

[spencerwilliams]

Why do we cross multiple? Thanks for the video.

[RamirezHD]

I was looking on how to interpret the null hypothesis for the odds ratio...but nice video.

[DPREY]

So, is it correct to say that "I can use OR in cohort studies only when the prevalence is very low (rare disease)"

[Wald]

Because the outcome is rare does that mean 1.11 is a big increase in risk

[geosui]

Very helpful video..I have a question though, even though it has not been mentioned in this video: how we calculate the logarithm of Odds Ratio?
for example, if the odds ratio is 0.71, how do we calculate InOR?

[crystal]

How can you tell the disease is rare or not rare if all that is given is the Odds Ratio is 5 (p > .001)?

[haarisarain]

watching this in 2020 feels very relevant.

[CraigDeLarge]

+elizabeth, Thanks for these. You are becoming my salvation in a course I am taking now. What markup device and software are you using in this video? I want to adopt it for work I am doing. Thanks for reply.

[peenleib]

Still don't understand why you can't use RR in case-control studies (in fact you have all numbers needed to calculate it). Could you explain it for me once again?