I just want you to know how much I appreciate your videos on biostats. As an epidemiology instructor I love using your videos for supplemental instructional material. I wish you were my instructor in my day!
Absolutely fantastic explanation. You have a natural talent for teaching, not just delivery but the clear breaking down into relevant sub-concepts and anticipating questions. Bravo.
This is the clearest explanation of odds and risk ratio on the internet. The video is very clear on why odds ratio is used in case-control study. I hope I am not being picky, but I do wish the author would use "for" and "against" terms and two whole numbers in discussing odds ratio. Yes, the video is the best. I am being picky.
+Rahul Patwari (Rahul's EM) Using your heart attack numbers, there are 10 patients in the group. 6 patients had a heart attack and 4 did not. I think gamblers would say the odds "for" a heart attack are 6 to 4. Gamblers might state the same relationship as the odds "against" a heart attack are 4 to 6.
I'm not a gambler, but I believe there are number of ways gamblers express odds. I was just going for the way the statisticians do it, but your point is well taken. Thanks!
The concepts couldn't be explained more clearly! Odds and risk ratios have confused me greatly throughout medical school and this is the first time I've ever had an insight and intuition into the concepts. Thanks so much!
You have single-handedly prevented me from crying over these concepts - I could not find a video for absolute and relative risk, so, if you were to make one (pretty please) I would be forever grateful : )
Thank you so much. There is a bunch of information on other courses butI couldn't find any playlist for epidemiology than yours.thanks for sharing it free🙏
I am also a MPH student overwhelmed over Epi module, this guy is soo good. His calm way of explaining it without rushing through it definitely helps as do the examples as they are all relevant
Awesome! Can not having mammograms and getting breast cancer be calculated with these scenarios? I really enjoyed the thoroughness and diagrams, which helped to clarify odds and risks.
I don't know why we cant use the risk in case control study? Viewer may take granted by seeing this video that Odds should be used for case control study while risk/probabilities should use for Cohort studies. Both can be used in either case , its not the study which decide what to use. Both has different way of expressing same measures
Hi Rahul, thanks for your good explanation. It really helps me a lot. Just a quick question. As you mentioned at 15:40, if the number in confidence intervals is 1 which means it is not statistically significant, which means there is no different, is it same if it is more than 1, like the example you gave 11.2, it is more than one and not statistically significant, does it mean it has no different too? Thanks Rahul.
This is absolutely amazing. The best explanation on OR and RR with relation to case-control and cohort studies. I guess cross-sectional studies would use OR as well and randomised controlled trials would use RR since they are an upgrade of the cohort study. Additionally, could you please explain how would we interpret the results of RR and OR? Using your example, would RR of 3 be interpreted as "those who take pills have 3 times more risk to develop MI than those who do not take pills" and would OR of 3 be interpreted as "those who take pills are 3 times more like to develop MI than those who do not take the pills"? Thank you for your videos.
I still don't understand why you can't calculate the relative risk from a case-control study. Once you put your data (exposed and non-exposed, diseased and controls) in a contingency table, you should be able to manipulate the data as you want, in the same way as you do in a cohort study, since both study designs use the same instrument (the contingency table) to analyze the data.
I guess you 've worked it out now, as it was so long ago that you posted your comment - but I had the same query, and I'm making this reply is in case anyone has the query too. In a case-control study, the numbers of people who are affected/not affected is more up to you. Maybe you have a group of patients who have had a heart attack (10 in his example), then you go looking for other patients who didnt have a heart attack to compare them with. Maybe you have 10 (as in his example) - or maybe you keep on looking, and find 20, or 30 etc. These will change the numbers in the contingency table and you will get different risk ratios (because you are deliberately searching out more people who didnt have a heart attack). However the caculated odds ratio will stay the same.
Wow, you are different. Thank you for such a great video. One question. If you do a retrospective analysis but you look at the effect of exposure on the outcome. (in my case, the risk of cancer recurrence depending on the duration of chemotherapy) Would you still use risk or logistic regression or what?
I am interested in using this video as part of a maintenance of certification test. This will require that the video be posted for at least three years. Do you have any plans to take this down?
I'm still confused with "we don't have that data". Can you explain why data is not available? Since we can calculate OD, we can use the same number to calculate RR. The difference between the two as you mentioned is whether the denominator include everybody or not include everybody. Also, do you mean that all case-control studies are unable to calculate RR? i.e. we will always see OD?
Can someone please explain what he did at 12:17 how did the pill stuff come to one side ? Sorry if it’s a dumb question . I’m 35 years old and my high school math is very rusty
![Coheed and Cambria - Searching for Tomorrow [Official Video]](http://i.ytimg.com/vi/hDsYGLbmadg/mqdefault.jpg)
It has been almost 10 yrs I came out of med school. But this concept is always a trouble maker for me. Thanks for the explanation.
I just want you to know how much I appreciate your videos on biostats. As an epidemiology instructor I love using your videos for supplemental instructional material. I wish you were my instructor in my day!
Absolutely fantastic explanation. You have a natural talent for teaching, not just delivery but the clear breaking down into relevant sub-concepts and anticipating questions. Bravo.
Excellent..Your calm voice added with a pint of humor and fantastic clarity made it easy to understand..Thank you so much
This is the clearest explanation of odds and risk ratio on the internet. The video is very clear on why odds ratio is used in case-control study. I hope I am not being picky, but I do wish the author would use "for" and "against" terms and two whole numbers in discussing odds ratio. Yes, the video is the best. I am being picky.
+Gene Sammons What do you mean by "for" and "against?"
+Rahul Patwari (Rahul's EM)
Using your heart attack numbers, there are 10 patients in the group. 6 patients had a heart attack and 4 did not. I think gamblers would say the odds "for" a heart attack are 6 to 4. Gamblers might state the same relationship as the odds "against" a heart attack are 4 to 6.
I'm not a gambler, but I believe there are number of ways gamblers express odds. I was just going for the way the statisticians do it, but your point is well taken. Thanks!
This is the clearest explanation I've come across on explaining Odds vs Risks
Well done sir, and thank you!
Very easy to understand. Thanks your nice presentation. We hope more videos with good examples.
Absolutely outstanding! I loved how you used drawing to explain and compare the formulas.
The concepts couldn't be explained more clearly! Odds and risk ratios have confused me greatly throughout medical school and this is the first time I've ever had an insight and intuition into the concepts. Thanks so much!
Dr Rahul, you are the best, and it seems as you have a great confidence. your way of teaching is unique and I love it, wish you well
This is the best course I have ever had regarding the main difference between OR RR.
Really I appreciate it a lot.
Many thanks+++
The perfect video answering all the questions I had from other videos. Thank you!
you are someone who really knows what is public health!!!! How great you interpret!!! thanks Patwari!!!
You have single-handedly prevented me from crying over these concepts - I could not find a video for absolute and relative risk, so, if you were to make one (pretty please) I would be forever grateful : )
I appreciate how clearly you lay out your teaching. I love the use of your pictures. Very very helpful for a newbie! Thank you
Finally I understood the differences between RR and OR! Thank you so much! Easily and simply
very underrated channel.. this channel should be much more popular
it's all about the denominator, baby LOL!
Thank you for clearing RR and OR it was really helpful :)
The explanation is easy to grasp, this has enabled me to solve a similar quiz. thank you
Great Explanation!!! Makes it easier to understand the difference in depth.
Thanks a lot! You explained odds in a very simple way that made it easy to understand.
This is absolutely amazing. Happy I found your channel. Hope you continue to make more videos. Thank you.
This really helped me to finally understand the difference between OR and RR! Thank you.
Thank you so much. There is a bunch of information on other courses butI couldn't find any playlist for epidemiology than yours.thanks for sharing it free🙏
Crystal clear explanation. It made great help for me. Thanks a million!
Great explanation, pitch perfect, thanks so much for the details it makes these odd concepts palatable.
Keep up the good work!
Current MPH student stressing over their epi midterm … thank you for this video!!
I am also a MPH student overwhelmed over Epi module, this guy is soo good. His calm way of explaining it without rushing through it definitely helps as do the examples as they are all relevant
Excellent and lucid... Thank you very much for sharing your knowledge
Outstanding clarity.
This is seriously the most helpful video I have seen on this. Thank you!
nice... I appreciate the way you simplify... You are a great teacher!
best review of probability and odds ratio yet! very very clear!
Thank you Dr. Patwari, your videos are easy to follow and very helpful.
Thank you so much for this video! So clear, so helpful.
EXCELLENT EXPLANATION, REALLY VERY HELPFUL
I have to thank you for your amazing explanation.
this is the best explanation I have ever seen, thank you so much!!!
very informative and to the point in clarity.............. thanks
Very excellent.. your explanation was completely clear thank you.
The clearest explanation ever! 👍
excellent! can you add some videos on study design and statistical tests that are used for example ANOVA versus spearman..
Good explanation but it would be better if the audio was little bit loud.
Thank you sooo very much this has been the best and simplest explanation!!
I genuinely think you might have saved me from failing my Epidemiology exam - thank you!!
Thank you that is the best and simplest explanation!!!
Great content💯...a must for step1 biostat prep
Brilliant
This is the first time I understand the odds
Fantastic explanations- THANK YOU!!!
This is a fantastic explanation, thank you
Awesome! Can not having mammograms and getting breast cancer be calculated with these scenarios? I really enjoyed the thoroughness and diagrams, which helped to clarify odds and risks.
Wow!!! That was great! I never understood odd ratio like that before ! Thank you very much..
I don't know why we cant use the risk in case control study? Viewer may take granted by seeing this video that Odds should be used for case control study while risk/probabilities should use for Cohort studies. Both can be used in either case , its not the study which decide what to use. Both has different way of expressing same measures
TheOraware
Mmxpojjv b. &$&& zVo
this is much better than any of the professors I asked!!! Thanks!
Really good. I applaud you good sir
Great job man, than you a lot. I almost got it but you helped me to fully uderstand it.
absolutely wonderful explanation.
Hi Rahul, thanks for your good explanation. It really helps me a lot. Just a quick question. As you mentioned at 15:40, if the number in confidence intervals is 1 which means it is not statistically significant, which means there is no different, is it same if it is more than 1, like the example you gave 11.2, it is more than one and not statistically significant, does it mean it has no different too? Thanks Rahul.
Now I even understand Odds as it's used in Betting😂🤣
Very nice illustration
Very well explained.. Thank you
Very nicely explained.thanks
Thanks for this great video. But I can not see any explanation about "risk ratio"!
DUUUUDE! I GOT IT! :) I watched like ten videos before and with this one I finally understood what odds ratio was! :) Thanks so much!
This is absolutely amazing. The best explanation on OR and RR with relation to case-control and cohort studies.
I guess cross-sectional studies would use OR as well and randomised controlled trials would use RR since they are an upgrade of the cohort study.
Additionally, could you please explain how would we interpret the results of RR and OR? Using your example, would RR of 3 be interpreted as "those who take pills have 3 times more risk to develop MI than those who do not take pills" and would OR of 3 be interpreted as "those who take pills are 3 times more like to develop MI than those who do not take the pills"?
Thank you for your videos.
thank you very much, it helped me a lot and you make it much clearer
Thank you very much. You are a great teacher
Crystal clear 😊😊😊❤❤❤ thank you 🙏
good up until 10min in or so, started to get foggy/unclear
Excellent explanation
In the last calculation, it would’ve been clearer to use the numbers from your study rather than symbols
Superb video.
I am not good at English. Thanks a lot.I watch several videos about odds ratio but I have known clearly odds ratio through this video
I still don't understand why you can't calculate the relative risk from a case-control study. Once you put your data (exposed and non-exposed, diseased and controls) in a contingency table, you should be able to manipulate the data as you want, in the same way as you do in a cohort study, since both study designs use the same instrument (the contingency table) to analyze the data.
I guess you 've worked it out now, as it was so long ago that you posted your comment - but I had the same query, and I'm making this reply is in case anyone has the query too. In a case-control study, the numbers of people who are affected/not affected is more up to you. Maybe you have a group of patients who have had a heart attack (10 in his example), then you go looking for other patients who didnt have a heart attack to compare them with. Maybe you have 10 (as in his example) - or maybe you keep on looking, and find 20, or 30 etc. These will change the numbers in the contingency table and you will get different risk ratios (because you are deliberately searching out more people who didnt have a heart attack). However the caculated odds ratio will stay the same.
this was the best explanation ever. thanks dude!
Dr. Patwari is it right to think of the risk=incidens and odds=prevalence? I am having a hard time understanding the relationship?
two weeks before boards. I come across this!! I dont how to thank you!!!
no one can explain this in a better way!
thanks a lot for the video, you saved my midterm exam !
Very nicely explained...
Sir, its a wonderful explanation. when do we get negative CI and 0.00 CI?
Wow, you are different. Thank you for such a great video. One question. If you do a retrospective analysis but you look at the effect of exposure on the outcome. (in my case, the risk of cancer recurrence depending on the duration of chemotherapy) Would you still use risk or logistic regression or what?
I like your explanation
well done help me a lot to understand
Br, it is very nice video, what is the difference between Cohort study and Randomized control trial , are they same or not ? thanks for your time
I am interested in using this video as part of a maintenance of certification test. This will require that the video be posted for at least three years. Do you have any plans to take this down?
+Donna Halloran Unless someone forces me to take it down, no plans to take it down.
Thank you for sharing. What program do you use to make this video?
Can you please give more explanation about the time direction in the 5:35
Thank you sir
Its very useful for me,🙏
Very helpful. 👍
Thanks - very clear and helpful.
you are a legend mate. thank you
I'm still confused with "we don't have that data". Can you explain why data is not available? Since we can calculate OD, we can use the same number to calculate RR. The difference between the two as you mentioned is whether the denominator include everybody or not include everybody. Also, do you mean that all case-control studies are unable to calculate RR? i.e. we will always see OD?
can you mention the playlist where I can get all the basic stats
excellent video! Thanks!
What software do you use for drawing in the slides?
Thanks again
+fernando rubinstein Vittle by Qrayon.
Great explanation!
Thankyou, this was extremely clear!
Very Very Useful
Can someone please explain what he did at 12:17 how did the pill stuff come to one side ? Sorry if it’s a dumb question . I’m 35 years old and my high school math is very rusty
Exellent explanation
Very helpful. Thank you!