Sophisticated statistics in medical research can be hard to translate to layman's terms, and when they are, these common misinterpretations can be downright misleading.
1. Odds ratios don't express relative risk.
In 1999, media reports resulting from a study published in the New England Journal of Medicine wrongly suggested that black patients and women were 40 percent less likely than white patients and men, respectively, to undergo cardiac catheterization.
The study's authors had used odds ratios to describe the significance of their findings—a common practice among statistically sophisticated researchers—which showed that black patients and women were definitely less likely to be referred for invasive procedures than white patients and men, but not how much less likely.