Sensitivity and specificity - explained in 3 minutes

Dr Greg Martin talks about the sensitivity and specificity of diagnostic tools used in global health programs. This forms part of the epidemiology series.
Global health (and public health) is truly multidisciplinary and leans on epidemiology, health economics, health policy, statistics, ethics, demography.... the list goes on and on. This TH-cam channel is here to provide you with some teaching and information on these topics. I've also posted some videos on how to find work in the global health space and how to raise money or get a grant for your projects.
Please feel free to leave comments and questions - I'll respond to all of them (we'll, I'll try to at least). Feel free to make suggestions as to future content for the channel.
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HERE ARE SOME PLAYLISTS
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WANT CAREER ADVICE?
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You can book time with Dr Greg Martin via Google Helpouts to get advice about finding work in the global health space.
Here is the link: bit.ly/GH_career
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Please watch: "Know how interpret an epidemic curve?"
• Know how to interpret ...
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[@MiilEastarr]

This is the most straight forward, easy and simplest explanation that I have found thus far...THANK YOU SO MUCH! I figured it out in the first minute let alone in 3. Why can't my lecturers be this simple

[@gregmartin]

+Coco Bongo Thanks for the comment!

[@joelnenadovich8141]

This guys is awesome. Lectures are idiots.

[@baldegl4422]

I agree, this was a exceptional summary of the salient features of these commonly used statistical methods.

[@GgG-71494]

play it at 0.75 playback speed.....youre welcome :)

[@maielmoutaz9017]

You're absolutely right, thanks 😂

[@Jenette818]

You're the greatest of all time my friend. I'm going to say a long prayer for you tonight and wish you blessings on blessings.

[@bizcaya]

Best video I´ve come across on the subject!

[@gregmartin]

Wow, thanks!

[@StudyWithM3E46]

wow seriously more helpful than my 12 minute lecture and the other youtube videos ive come across. thanks a lot!

[@MARTINAEFEYINI]

Thank you for sharing and posting! This is short, to the point and easy to understand.

[@gregmartin]

+MARTINA EFEYINI Thanks!

[@janesmokie]

Great, clear, conscience explanation. I’m glad you took the time to explain the difference between the predictive values and sensitivity without over complicating it.

[@rebeccaleverock1689]

I have also looked at many videos to understand sensitivity and specificity and yours by far was the simplest and easiest to understand! Thank you so very much!

[@gregmartin]

Thanks Rebecca - that's very encouraging! Glad you liked it!

[@patriciaschwerdtle5789]

Just when I thought I was facing rubbish-throwing nursing/midwifery/paramedic students tomorrow (again).. predictably Greg Martin comes up with the perfect

[@gregmartin]

Patricia Schwerdtle thanks very much for the comment !!! you are too kind.

[@zekihi6994]

Wow, really useful. This video really solved my confusion why choose (TP+FN) as the denominator of sensitivity. "So, that, it's not affected by the prevalence of the specific disease." Thank you!!!

[@gregmartin]

Glad you found it helpful Zeki!! thanks for the feedback.

[@dr.yamanfawal9419]

OMG, sir i owe you so much. This is the first time i deeply understand this topic.

[@jimileekalu7275]

Dare I ask? Oh, why not... please consider an episode explaining Direct & Indirect Standardization. Thank you sir. Love your channel!

[@gregmartin]

Thanks for the suggestions Jimilee Kalu - great idea. I'll do something on that soon for sure!

[@taylorbrooks754]

Oh my gosh, I almost had an aneurysm trying to figure this out by myself. Thank you so much for making it so simple!

[@gregmartin]

So glad it helped, thank you for your amazing feedback!

[@davidalexander829]

Excellent. Just the level and depth of detail that I need briefly. Thanks!

[@essadjama5139]

Thanks Greg Martin. i learned from you so many things since the last four years, perfectly explained.

[@Samirabrown123]

subscribed specifically because I liked your sign off phrase.

[@gregmartin]

haha - well that is as good a reason as any - thanks for subscribing! Hope you enjoy the videos...

[@camhaw]

Best video!!!! I've been reading and trying to understand those terms forever and I got it now... in 3 mn! Thank you Greg!\

[@gregmartin]

You are most welcome! Glad that I could help!

[@denaconley2883]

Thank you so much for this amazing video! Very straight-forward way of explaining a concept that is is otherwise presented in a different language in class :) The differentiation between sensitivity/specificity and +/- predictive value: Extremely helpful; never thought about it like that. Thank you!!!

[@gregmartin]

Glad that you found it helpful Dena! thanks for the comment!

[@fgnsdfnbnd4908]

Sensitivity- tests positive correctly/all people positive -TPC/APP
Specificity-tests negative correctly/all people negative-TNC/APN
Positive predictive value- tests positive correctly/tests positive-TPC/TP
Negative predictive value-tests negative correctly/tests negative-TNC/TN

[@luchewei]

You totally answer and interpret a confused topic clearly!

[@gregmartin]

Glad I could help

[@mikehynz]

I can't believe I almost never knew that. Well done!

[@raymeyer1825]

This was very easy to understand, I had a lecture this morning about sensitivity, specificity and PPV and NPV it was unclear now I understand it clearly. Thank you

[@gregmartin]

Glad I could help Ray - thanks for the feedback!

[@Theprofessionalsurgeon]

that was the best explanation ive ever got

[@gregmartin]

Wow - what a nice thing to say (thanks!!)

[@shyama5612]

Crisp and clear explanation. Nicely done.

[@gregmartin]

Thanks for watching!

[@singinglovehearts]

I needed this refresher. Thank you!

[@gregmartin]

You're most welcome. Do let me know if there are other topics that you'd like me to cover.

[@baezledesma3439]

Great explanation!! Absolutely useful, 3 mins video, thank you!

[@gregmartin]

Glad it was helpful!

[@SarahRN]

thank you. simplified so its easy to understand.

[@pendapalanamundjebo5328]

Hi just wanted to say this video is a life saver. It was really simple and easy to follow. thank you.

[@gregmartin]

Penda Namundjebo thanks for the comment - that is very kind of you to say. Please feel free to send me any suggestions re future content.

[@pendapalanamundjebo5328]

Global Health with Greg Martin I have an assignment on age standardisation ratios and i saw someone asked you to make a video on that. I understand that you obviously cant help me directly with the assignment you know, academic integrity and all but if you can make give me a link to some good sites that would be good. The problem with the question in my assignment is there is just one population group and i dont know whether i'm meant to make up my own standard population.
anyway i loved your other video on cohort and case study. your students are lucky to have you.

[@gregmartin]

Penda Namundjebo hi there -thanks for the reminder - I'll put together a video on Standardisation very soon

[@af121x]

Thank you. This is the clearest explanation I found.

[@gregmartin]

Glad you liked it. Thanks for the feedback.

[@nureyna629]

Best understandable sensitivity and specificity video ever, thank you so much...

[@gregmartin]

You are most welcome Muzdalifa

[@user-uy3qf5sd6l]

still helpful after 10 years 🙂! thank you...

[@gregmartin]

Glad you liked it, thanks

[@halimahmohammed5849]

I went in thinking I wouldn't understand, but your explanation is simple.

[@gregmartin]

I'm so glad that I could help!! Thanks for the feedback Halmimah.

[@4489005]

Perfectly explained with a great smile. Thank you sir.

[@drramburnjennu6478]

Hello Greg Martin ,thank you so much for making Public health so much simpler.Your videos are the best I've watched.

[@gregmartin]

+Jennita Ramburn - thanks for your very kind comment. Much appreciated. 😁

[@indrashispowali]

thank you Sir for your such lucid explanation

[@gregmartin]

You are most welcome

[@pei-enhuang4858]

Thanks you for such good explanation and illustration！！

[@e.awdishu_MD]

Thorough, clear, and easy explanation. Thanks!

[@gregmartin]

+Emmanuel Awdishu glad you liked it - thanks for the feedback.

[@olufunkeadeniyi1584]

Thank you so much for this
Very easy to understand

[@kdramaaddict5241]

Thank you very much ....you explained so simply, I was worried about this topic.You help me a lot. May Allah bless you with all His blessings

[@gregmartin]

Thank you very much for the kind comment (much appreciated).

[@tungstenwhizard4361]

I don't know why this topic was so difficult for me to understand. I am in a practicum course at my uni and I could understand most things but not this! Thank you so much

[@gregmartin]

Glad it was helpful!

[@akankshagaur1626]

Really helped me. Thanks for making it easier than the books

[@ibda3color]

This is Wonderfull, really appreciated

[@gregmartin]

Thank you for the feedback!

[@vijaypalmanit]

best explanation so far, finally i understood the concept.

[@gregmartin]

I'm so glad Vijay! Glad that I could help.

[@zarsblackhorse123]

Thanks for explaining easily in a short period of time.

[@gregmartin]

You are most welcome Zarif! :)

[@verasndergaard8156]

Simple and easy to understand. This helped me a lot. Thank you sir. Vera

[@gregmartin]

Glad you liked it Vera - thanks for the comment.

[@haideralwaeli1398]

Thank you, like the few minutes explanation to the topic,, thank you
Can you relate to what the positive and negative predictive value of the test will add to our explanation of the sp and sn of the test. I believe in your style (simple and clear)

[@GregMartin123]

+Haider AlWaeli - thanks for the comment!

[@heba_seyh9]

On word only “ AMAZING”

[@gregmartin]

Thanks!!

[@mamirmemon4938]

Hi Greg, Amazingly explained in simple words. Fantastic! Would you please recommend any other 3-minute video of yours or others on Negative and Postive Predicted value. This i couldnt understand from the last one minute of yours. Thank you!!!

[@gregmartin]

Hi there Amir - thanks for the feedback. I don't have a video out at the moment on predicted value but will create one shortly.

[@saz4217]

Thank you very much

[@gregmartin]

You’re welcome

[@DragonRider520]

I watched a 13min video and couldnt understand what specificity is.. Completed understood it after 1 min of this video.

[@gregmartin]

Glad to hear it!!! Thanks for the feedback!!

[@dianecalabrese228]

What an incredibly easy explanation...Thank you !

[@shanegordon9586]

This was really good. Very clear. Thank you

[@fatheringexcellence]

Perfectly clear. Thank you.

[@gregmartin]

Thank you for the feedback. Glad you enjoyed it!

[@annetteb.collins9540]

Oh, and Thank you for creating and posting!

[@gregmartin]

You are most welcome Annette Collins

[@Med.School.Survival]

Great presentation Greg :)

[@gregmartin]

+EpiStats Thanks

[@thejohnarnett]

best video I've found so far for sure! You're great at what you do! :D God bless :D

[@gregmartin]

Thanks for the very kind words John - I really appreciate it!

[@doctormwpepper]

Thanks Dr. Martin

[@gregmartin]

You are most welcome Hassan. :)

[@inatorist]

Thank you!

[@etherealbae2160]

You explained this wonderfully. Thank you!!

[@user-db6yc6hd2e]

Amazing explanation thank you

[@gregmartin]

Most welcome, thanks for watching

[@MsBossanova]

Love the way you explain!

[@gregmartin]

+Loreto Carmona Thanks a lot Loreto!

[@spiveyweb]

thank you Greg Martin.

[@gregmartin]

spiveyweb you are most welcome 😁

[@rayanballuz]

Thank you

[@yasminkhattab3473]

thank you !!

[@gregmartin]

You're welcome!

[@sebtacular]

Thanks, this was really helpful!

[@mohabad2730]

Thank you Doctor!

[@justinebugeja]

Finally understood it! Thank you

[@gregmartin]

Glad I could help Justine Bugeja

[@corneliaezima312]

Thank you the explanations. Great work

[@gregmartin]

Thanks for the feedback Cornelia - much appreciated. Glad you liked it.

[@beverleykang9458]

very clear and helpful thank you!

[@brrrr4]

Hi, many thanks for your brilliant videos, exceptionally good explanations.
Do you have any chance to explain how to do data analysis, particularly how to select appropriate tests like chi-square, t-test, paired t-test, anova etc.?

[@gregmartin]

Thanks for the question brrrr4 - I have done a few videos on data analysis (but haven't yet covered the topics that you suggested). I will certainly be doing more and will cover the areas that you've indicated. In the interim, you can go to my How to Find and Use Data playlist and see what I've done so far: th-cam.com/play/PLujS9ooBebKVqwKXDqdqMqkwb1EKl4FM6.html

[@brrrr4]

Hi Greg, Many Thanks for your extremely quick response and your brilliant suggestions. I am looking forward to learn further from you, you have got talent on teaching.

[@GregMartin123]

+brrrr4 - great question - i'll make a video on that sometime.

[@Happy.Traveller]

Hello Greg, I have a question. If the test is not 100% accurate, then how do you know the total number of people who actually have or do not have a disease?

[@DoctorQsFM]

Scientists have what is called a gold standard. Oftentimes, the gold standard is the patient autopsy.

[@nakshatralakshmi7869]

Thanks a ton

[@asegahegnshigut6981]

excellent presentation

[@gregmartin]

Thank you! Cheers! Glad you like it

[@dorismarufu2294]

Thank you. This is so helpful

[@user-jh1ct5hu6m]

so simple and nice

[@GregMartin123]

+‫نهلة حسن‬‎ Thanks

[@fionascorgie4293]

Nice, using this for a training next week!

[@gregmartin]

Glad to hear that you found it helpful!

[@godwinogbole8834]

great presentation

[@gregmartin]

+Godwin Ogbole Thanks Godwin - much appreciated.

[@Sly922]

Absolute king

[@tarheelpower2]

Genius explanation

[@gregmartin]

You are very kind to say so (thanks)

[@TheShabooka]

Sharp and straightfwd explaination
Thanks :)

[@gregmartin]

Hi Shabooka Zalaknke thanks for the comment. Glad you liked the video!

[@kh-wg9bt]

Clinically then, high sensitivity is more important when using the test in a diagnostic context with symptomatic people with a suspected illness?

[@kingryanPvP]

Helped me for my Stat class. Thank you.

[@gregmartin]

Hi Mor - I will be making statistics videos shortly (so watch this space). Greg

[@mdyounusahamed6668]

Thanks.

[@gregmartin]

Welcome!

[@tominkurisunkal886]

wow this helps so much

[@gregmartin]

Thank you for watching! So happy to hear that!

[@tominkurisunkal886]

@@gregmartin definitely! Had to learn it real quick before my final exam and I sure used it in the exam too. What a legend fr 💯

[@salmansohailchaudhry]

Thankyou

[@asseelhamza789]

thank you

[@gregmartin]

Most welcome Aseel!

[@emeyekey5161]

Great vid! - Nice and concise

[@gregmartin]

+Matthew Kakande thanks. 😁

[@rancorslayer5228]

Love the outro

[@gregmartin]

Thanks for the feedback

[@Zahrani024]

great job!

[@gregmartin]

Thanks

[@mokhadra9289]

Great explanation... Thank you..

[@gregmartin]

+Mohammad Khadra Thanks for the feedback - glad you liked it.

[@naveengajula9942]

REALLY SIMPLE N SWEET

[@gregmartin]

Thanks (appreciate the comment)

[@SoniSoni-su4hh]

great videos for sure. what software or programs do you use to create videos like this?

[@gregmartin]

Hi Soni - I use Final Cut Pro X and KeyNotes for a lot of it. Hope that helps. Greg

[@ellahaoryakhail98]

My mind is going out 💥 every time I hear taste instead of test

[@gregmartin]

haha - will try to do better

[@kimberleychan4378]

THANK YOU SO MUCH!

[@gregmartin]

You are most welcome Kimberley

[@bunidan2381]

love your work!

[@gregmartin]

thanks buni dan

[@MsFresh4444]

Great video! Subscribed :)

[@gregmartin]

Thanks. Glad you liked it. Thanks for subscribing!! 😀👍☑️‼️

[@thegamefoshoz]

You are the best !!!!!!!!!!!!!!!!!!!!! THANKS !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@GlobalHealth101]

+Lester Mendoza glad you liked the video Lester - thanks for the feedback.

[@naveengajula9942]

THANK YOU

[@gregmartin]

You're most welcome ! :)

[@zafreacts1587]

Problem solved. Thank you

[@gregmartin]

Glad it was helpful! Thank you :)

[@DOC_951]

This is gold

[@gregmartin]

Glad you found it helpful Jason!