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Penn and Teller on Relative Risk

By Dr. Sujatha Prabhakaran

I love magicians.  In my day job,  I’m a concrete thinker like many physicians, but set me in front of someone doing card tricks and I am mesmerized.   And while I know there is some rational explanation for how the magician knew I picked the three of hearts out of all the other cards, I can’t help but be amazed. The ease with which I accept magic I think says a lot about how easily our brains are fooled into believing something we know is not sensible.  Take for example, irrational fears about the risks of vaccines and contraceptives. 

After the HPV vaccination was introduced, stories circulated about the risk of death from the vaccination.  They had headlines such as “Jabs as bad as cancer” (jabs is the charming British term for injection) and “Deaths from HPV vaccine rolling in”  When patients come in with questions regarding these headlines, it can be difficult to find a way to explain the risks to them in a way that is understandable.  We don’t want to diminish real risk, but we also need to put it in perspective.   One great way to do this as physicians and potential policy influencers is to make abstract ideas concrete with visual representations of risk.  A great example regarding the HPV vaccination risk is from a website call Information is beautiful.  The illustration featured here comes from the site and puts into perspective the actual risks surrounding HPV vaccination and while not saying that there is no risk, the visual representation does a great job helping convey the relative risk. 

Another great tool for conveying risk is the Paling Palette.  You have likely seen these Palette of stick figures used to convey risk.  Here is one I created to convey the relative risk of DVT at baseline, with contraceptive use and during pregnancy.  This palette actually conveys what 10 times each of the risks are because the palettes only hold 1,000 figures and these risks are per 10,000.  But as you can see from the palette, while the risk of DVT on combined hormonal contraceptives is four times the baseline risk, the risk is still low and about one tenth the risk during pregnancy. 

And finally Penn and Teller who usually spend their time pulling the wool over our eyes, here are working to dispel a medical myth with a graphic representation.  Penn and Teller weighed in on the hypothetical relative risks of autism from vaccination versus the risks all the diseases we are protected from by vaccines.  This video is risqué, but I think it does an obvious, if dramatic job of conveying a concept we all believe, but might have a hard time conveying to our patients and to policy makers.   These are just a few ways we can convey our data to our patients and policymakers in a way that makes it useful to them, which in the end is the purpose of data, right? 

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