They are everywhere. Research articles, abstracts, press releases, and news articles touting that such and such will DOUBLE THE RISK of some dread happening. Or cut the risk of some dread happening in half, depending on what slant they want to take on it.
Describing risk this way makes small differences seem large. Which is exactly what you want when you’re a news outlet clamoring for the attention of readers. Or a university PR office trying to attract public interest in the research happening on campus.
But it’s a terrible way to evaluate risk. Say there’s a common medication being used in hospitals, and a new study looks at this medication to evaluate the risks. This study finds that the medication raises the risk of the complication from 1 in 10 million to 2 in 10 million.
Yes, *technically* that’s double the risk, but it’s not a huge difference in the absolute risk.
Any time you hear risk being described with multipliers like this, take a look at the absolute risks described in the study, and communicate that information in a better format to your client.