Relative Risk – Making a Mountain out of Molehill

A few times a year we’re told by the journalists that some big scientific study at some big university found that doing something we all love to do, like eating bacon and eggs, is 50% more likely to lead to early death than eating yogurt and berries. Then the next week the yogurt is the culprit, causing some malady or early death, which, of course, we are all trying to avoid.

Has science gone mad?

Well, those clever scientists have a trick they use to make benign occurrences sound horribly scary. It’s called relative risk and even sometimes “RR” since they think if they hide the word “risk” with an abbreviation you won’t be able to figure out that this ominous occurrence is something akin to your chances of winning or losing at the craps table in Vegas.

So, what is relative risk?

Let’s take an example. Assume that we have some data that shows that out of 2,000 people that eat breakfast, half of them eat yogurt and berries and the other half eat bacon and eggs. In our hypothetical example let us also assume that 2 out of every 1,000 yogurt eaters get the hiccups after breakfast. And 3 out of a thousand eating the bacon and eggs get the hiccups.

You and I do not need a scientist to figure out that the resulting hiccups probably had more to do with the orange juice they were drinking, or which morning television show they were watching. Kathy Lee Gifford always gave me the hiccups and after an occasional toddy on the show, she’d have them too.

Now when the epidemiologists issue a report on this little experiment that cost taxpayers 3 million dollars of hard-earned cash, they’ll tell you that based on their experiment, people that eat bacon and eggs for breakfast are 50% more likely to get the hiccups than people that eat yogurt and berries. And, of course, they would technically be correct, since 3 is 50% bigger than 2 (or at least it is on my iPhone calculator).

But we’d both probably concur that this nominal difference is nothing to be alarmed about.

So next time you hear the ominous news of the dangers of consuming something you love you’ll know that more than likely, it’s Kathie Lee Gifford’s fault.