Let's communicate risk clearly

doi:10.1136/bmj.b3034

Published 28 July 2009, doi:10.1136/bmj.b3034
Cite this as: BMJ 2009;339:b3034

Letters

Statistics for health

Let’s communicate risk clearly

The first 150 words of the full text of this article appear below.

Heath understates one important issue in her observations onbreast screening¹: the systemic illiteracy of doctors, epidemiologists,and other health professionals in communicating statisticalresults.

Gigerenzer pointed out just how badly professionals misinterpretrisk when given the data as conditional probabilities.² He contrastedthis with the (much improved) results when the facts are communicatedas natural frequencies. Despite this we continue to use theformat that doesn’t work.

I have used the statistics around screening for HIV, prostatecancer, and breast cancer to show decision makers why the wayyou communicate the facts affects people’s ability tomake sense of them. Surprisingly, public health people in theNHS are often shocked at the implications of the statisticson breast cancer screening once they understand them (they oftenseem to start with a belief that mass screening programmes arean effective public health intervention).

We need to stop assuming that . . . [Full text of this article]

Stephen Black, management consultant¹

¹ London SW1W 9SR

steve.black@paconsulting.com