Fact-Checking Standards

What we check

• Claims about symptoms, causes, treatments and outcomes
• Statistics, including their source, date and population
• Citations, to confirm the source says what we say it says
• Quotes, attributed accurately and in context
• Names, titles and credentials

How we check

Fact checkers trace each claim to a primary or authoritative source, confirm the strength of evidence, and flag language that overstates certainty. Where evidence is limited or mixed, we say so.

Evidence language

We use careful language to describe research: “is associated with,” “may help,” “evidence suggests,” and “guidelines recommend” each mean different things. We avoid “proves” and “cures.”

When facts change

If new evidence changes our understanding, we update the page and note the update date. See our corrections policy.