Risk numbers, made real

A treatment cuts your risk by 25%? See what that means for 100 people like you — and the exact question to take to your GP.

Pick a common decision, or pop in a percentage you were quoted. You'll get an honest picture — the upside and the downside side by side — that you can take to your appointment. Nothing you enter leaves your browser.

This tool needs JavaScript for the interactive picture. The short version: a "25% lower risk" usually means the relative figure. The number that matters for a decision is the absolute one — how many out of 100 people like you actually avoid an event over a stated time. Bring both numbers, plus the harms, to your GP and ask what your own baseline risk is.

Pick a common decision

Each option uses cited Australian / primary-source numbers. Time horizon comes from the source.

Your own starting risk (optional)

Not sure? Leave it on "I don't know" — that's the honest default, and the tool will show you a range.

Or tap an example

The percentage your risk drops by

How much the headline number shrinks the risk — the "relative risk reduction" you were quoted, e.g. "cuts your risk by 25%". A whole number, 0 to 100.

Over what time? (required)

If you know your own risk over this period (%) — optional

Worked example — the kind of picture this tool draws

Take the first scenario in the list: a statin to prevent a first heart attack or stroke, over 5 years (Cholesterol Treatment Trialists' Collaboration 2012, Lancet). The headline figure is "25% lower risk" — that is how much the headline number shrinks the risk (the relative risk reduction).

The real number out of 100 (the absolute difference) is smaller than it sounds. For 100 people at average starting risk, about 2 in 100 avoid a heart attack or stroke over the 5 years — the other 98 see no change either way. Said as a frequency: roughly 1 person in every 50 avoids an event; the other 49 are unchanged. Both numbers are true — they answer different questions.

The other side of the ledger, from the same sources: about 1 in 100 may develop type 2 diabetes who otherwise wouldn't, and about 5 in 100 report muscle aches — though blinded trials show most of those aches also happen on a dummy pill.

The question to take to your GP: "What's my own baseline risk over 5 years, and what does that make the absolute number for me?"

General information to help you prepare. Not medical advice and not an emergency service. These numbers are general illustrations, not your personal risk. In an emergency call 000. Lifeline 13 11 14.

A treatment cuts your risk by 25%? See what that means for 100 people like you — and the exact question to take to your GP.

Two true numbers, two different questions

The one question to take with you

Take it with you