NCCMT - URE - What’s the Risk? Understanding Absolute and Relative Risk Reduction

Video created: May 10, 2016
Studies on the effectiveness of public health interventions can present the results in different ways. Knowing how to interpret these results will not only help you understand how effective an intervention is, but also how meaningful it will be to your population.
In this eight-minute video, we look at how three statistics - baseline risk, relative risk and absolute risk - are connected and how using them together can help you make better informed public health decisions.
The video uses the example of injury prevention in a senior population to demonstrate how absolute and relative risk reductions are calculated.
Greater understanding of these statistics will help you apply evidence in your practice, contributing to enhanced public health outcomes.
The National Collaborating Centre for Methods and Tools (NCCMT) is one of six National Collaborating Centres for Public Health in the country with a collective mandate to strengthen public health in Canada. Visit the NCCMT website (www.nccmt.ca) or contact [e-mail] for more information.
Production of this video is made possible by financial contribution by the Public Health Agency of Canada. The views expressed here do not necessarily reflect the views of the Public Health Agency of Canada.

[@sosac6646]

This was honestly really good. Using the same example for all the risk ratios was so helpful. Seeing how it compares.

[@mbangaclarence7082]

Excellent video. I had been struggling with these concepts for a while now. Thank you so much for the video. The illustrations are pure Gold. Makes the whole thing so very easy to understand.

[@omarjea]

Hands down, this was the best video I've watched on understanding the logic and visualizing what AR, ARR, RR, and RRR. Kudos!!

[@nccmt]

Thank you! We are glad you found this video useful.

[@IceDr4gonfly]

This is pure gold. Amazing video! The explanation was clear and illustration helped a lot. Thank you!

[@ipsitahamidtrisha6379]

This is the best video I've ever seen on these concepts! Amazingly illustrated and explained!!! Thanks a zillion times!!!

[@LA-hg1tx]

thank you very much, it made if very easy to understand and calculate

[@georgiehenderson8750]

Very well and clearly explained. Thank you very much.

[@angrant2014]

Thanks for explaining this so well and concisely.

[@heartleaf88]

Wow. i learned so much in 8 minutes. Thank you

[@florencemwango6243]

Very good explanation for complex concepts!

[@wildfirekunal]

These videos are great. Thank you!

[@cartoongamess1]

Thank you so much for a wonderful talk!

[@LuisaneVieira]

Amazing course.

[@lindawebster6325]

Good explanation. I appreciated the graphics.

[@lamaaldosari7835]

you are brilliant!!!!!

[@Rafiq2024A]

I have developed my own formula for this purpose: You see ARR is 12% and AR is 30%. I divide ARR/AR; i.e, 12/30 which is 0.4 (40%) which gives me the relative risk reduction and automatically I will understand that the remaining risk is 100-40=60% ! Because the total will not be more or less than 100% and it is always fixed! But actually I appreciate your work because I learned the concept from you!

[@je6874]

Amazing video

[@jeffreydalli7547]

excellent video

[@compier12]

Thank you

[@martian2030]

awesome.

[@emiliaantoniasotonenadovic214]

Señora la amo

[@shaikshafi1284]

Excellent

[@sweswelattdr2964]

excellent

[@tetianatkachuk3013]

thank youuuuuuuuuuuu

[@BN-hy1nd]

Help! I am just interested.This is all new to me. In a layman's lamnguage, does 1 - the relative risk reduction (RRR) tell us how effectivve/efficient the intevention/training is??

[@nccmt]

Hi, thanks for your interest. Relative risk reduction tells you how much an intervention lowers the risk specifically in comparison to the control group. This means relative risk doesn’t tell you how effective the intervention is for all populations, but only relative to the control group. The reason is that it does not account for the individuals’ baseline risk of the outcome in the absence of the intervention. To calculate the Relative Risk Reduction (RRR), you subtract the Relative Risk (RR) from 1, so RRR = 1 - RR. Absolute risk, on the other hand, accounts for baseline risk and is a better and often more conservative estimate of the effectiveness of an intervention.

[@vanessatorres7845]

at 5:54 you said the AR is 6%. From where did you obtain this value (6%)???

[@nccmt]

Hi, in this example, the Absolute Risk for fractures with no intervention was 10%. We know that the intervention has a Relative Risk Reduction of 40%, so that means the risk of fractures with the intervention is reduced by 40% of the total risk. To calculate the Absolute Risk in the intervention group, you subtract 40% of the Absolute risk. In this case, it’s 40% of 10%, or 0.4 of 10%, which is 4%. That leaves you with 10% - 4% = 6% Absolute Risk of fractures in the intervention group.

[@sammyjo8935]

@@nccmt "That leaves you with 10% - 4% = 6% Absolute Risk of fractures in the [intervention]* group" no?

[@nccmt]

@@sammyjo8935 Hi Sammy! You are correct; the last sentence above should read intervention group and not control group. Thank you for catching that. The comment has been updated.

[@adhipmitra]

Very lucid.

[@philipbrown2225]

clear as mud

[@Helloomi97]

A low baseline risk means that the *absolute risk reduction* will be lower (despite *relative risk reduction* remaining the same) 6:55

[@SgtMajorSav]

I wonder how many people looking at the vaccine will be like "oh, ok so relative risk does mean something after all" alot of people out here looking at the lower absolute risk and running with that. Relative risk for smoker who develop lung cancer are 7 times higher than non smoker but the absolute risk is only 3% will develop lung cancer than non smokers.... so 97% chance smokers wont develop lung cancer.. smoke up folks!

[@M.-.D]

@@SgtMajorSav I would do a lot to avoid a 3% risk of developing lung ca in my lifetime. Fortunately I get 2.5ish% just by not smoking.

[@ytcdi]

And the 2023 Oscar goes to RRR !

[@bobimarkers3657]

Anyone watching this to figure out what these numbers mean for jaaaabzzz?

[@vicmercd9136]

That means don't take that poison

[@russcarroll1648]

@@vicmercd9136 you said it!

[@Troo-Thirts]

Video called "November 12, 2021" by zay truth 333. It ends up going from 95% efficacy rrr to 1% arr, and that's before the recent admitted lowering of efficacy. Less than 1% protection and all the risk from taking it. Where do I sign up? 🤣😂🤣😂🤪

[@jackgartlan]

5:45 "The intervention group's risk of a fracture will be 40% (RRR) of 10% (Control AR), which means the absolute risk in the intervention group will be 6% (Intervention AR)." Just wanting to point out that this is actually 40% less of 10% ( 10 - (10 * 0.4) = 6 ), not 40% of 10% (which is 4%). Great video however, just clearing this up because it's an already confusing topic.

[@nccmt]

Hi Jack. Thanks for pointing this out! You are correct that the intervention group’s risk of a fracture will be reduced by 40% (RRR) of 10% (Control AR).

[@randomness3235]

The CCCA did a much better job at explaining how people were bamboozled by this.

[@cu99460]

Im confused as fuck

[@ThatFellaChris]

Total ludicrous what she says, where did she got the 30 % from????

[@nccmt]

The 30% figure was calculated based on the hypothetical scenario where in a 300-person control group, 90 experienced fractures, so 90/300 = 30%.