Definition
Plain language
A number for how much more often something happens in one group than another — one means no difference, higher means more likely.
As stated in the literature
The ratio of the odds of an outcome between exposed and unexposed groups; in observational EHR analyses, adjusted odds ratios above one indicate elevated risk after controlling for covariates.
Why it matters: It matters because it puts a single interpretable number on how strongly two things are associated, guiding what's worth investigating.
For example, an odds ratio of 2 means people taking a drug had twice the odds of a side effect compared with those who didn't.
Heard on the show
“All of them came back flat — no signal, odds ratio essentially one.”Episode 187 — An 8-Billion Agent That Beats Models 80 Times Its Size By Looking Things Up