Hazard Ratios and Survival Curves

A brief conceptual introduction to hazard ratios and survival curves (also known as Kaplan Meier plots). Hopefully this gives you the information you need to interpret these numbers.

[setareeslami]

Dr Patwari! you're an unbelievably amazing teacher! appreciate all your time and effort for all those precious videos

[manotelotrakul]

Thank you! I was confused about how to apply the RR and HR . Now I'm cleared.
Your lecture is very helpful. You are a mavellous teacher.

[fetabrown]

That was so helpful, just what I needed today on my masters in public health journey!

[arinarakhteenko]

Thank you for that beautifully explained details!

[hether]

This was a super helpful review of these concepts. Very easy to understand and follow for the non statistician. Loved your animations !

[Turtleking]

Amazing! Thank you very much. We have an exam tomorrow and our professor recommended that we watch this

[rusabbaig]

Thank you so much Dr, you're a life saver

[ivanmazur]

Great explanation! Although on 0:51 you say "edit that out". I assume you didnt want that in the final version

[masoudisanejad]

saved a lot of time watching this video complementing with the text, thanks

[bjurv]

Thank you! Just one question. You say that Hazard ratio is the probability for an event to take place in a given time interval. In the table of Vitamin D levels and death that you use in the beginning of the video I can't see that the specific time interval for the hazard ratio is noted/specified, shouldn't a time intervall för the hazard ratio be specified then? (Maybe the time intervall was made clear in the text of the study?)

[MedicalNemesis]

Well, so what does the hazard ratio that is written out in the beginning mean? What interval are we talking about? Isn't the point of Hazard ratio compared to RR to define a certain interval so we can see who is more likely to die in that interval? Otherwise why can't we just use RR? Shouldn't there be several hazard ratios presented, one for each interval??

[moonblad]

How do I get a P-value comparing 1-year survival rate between two groups? What method should I use and what variables should I use?

[jamesfilosa]

Could you please explain why your hazard ratios aren't exactly in the middle of the confidence intervals? Does it have to do with lognormal distributions?

[fritsvanzanten]

6:27 You call the percentages ( 19% and 6%) 'hazard rates'. I'd guess the ratio then would be 16/9 (comparing the hazard rate). But this is not mentioned. Is the hazard ration the same as the hazard rate, or is it the ration of both? I also don't understand why they should be the same (I guess that's under the H0, no difference hypothesis). Still, nice video, very clear and (important) enjoyable.

[agusta]

Great Job, Dr. Patwari!!! May you possibly have any worked examples for Board exam purposes? Thank you

[yasminelsobky]

I got the idea that hazard ratio time element is important. but I didn't get the idea of "the hazard ratio is 2.5 it means that in a particular given interval, one group has a 2.5% 2.5 times more likely chance of experiencing the event (in this case death) then the other group does." how can i know this particular time from the table??

[thanyapathirana]

Thanks a lot. Could you please add a video on likelihood ratios and pre-post test probabilities?

[abebemulugeta]

you are nicely stated the case. thanks

[lkgurmer]

I absolutely hate biostat, but not when it's made this easy! Thanks!

[phMoca]

This is very helpful. Thank you a lot. :)