Scan the health pages on any given day and you're likely to see a headline about the risk of a medical condition being increased or decreased by a food or activity. Today, for example, it's Vitamin E and strokes. Understanding what these risks mean to our lives is just one example of the importance of statistics in health.
Probably the most important thing to understand is the difference between relative and absolute risk. Relative risk is the one most often found in the headlines: it's the ratio of the risk of people affected by the factor being studied to the risk of those without it.
For example, a Google search for "doubles risk of cancer" turns up over 100,000 hits, with HRT, diabetes, weight gain, cigarette smoke and solariums among the suspect factors on the front page. But the point that's often missing is whether the risk is being doubled from something tiny or something large.
If one in a million people die from a condition, then 'doubling the risk' means two people in a million will die. It's probably still not worth worrying about. The absolute risk tells us about how many more people will be affected; not the proportion.
Training journalists who don't have a scientific background in topics like reporting risk was identified as a priority by the government's Science and the Media group earlier this year. That led to my appointment to a position, hosted by the Royal Statistical Society, to coordinate this activity. The RSS was chosen to host the job because statistics is crucial to so many science and health stories. Science is all about data, and statistics is the language of data. The RSS has also just launched an ambitious ten-year campaign, getstats, to increase statistical literacy across the entire UK population.
On 1 December, the RSS will be hosting a workshop for journalists entitled 'Health and Wellbeing: the Stats Behind the Stories'. We've got a panel of leading statisticians, with wide experience of working with the media, to look at recent health news stories, such as swine flu, and tease out the thorny statistical issues behind them. On risk, for example, we have David Spiegelhalter, Professor of the Public Understanding of Risk at Cambridge University and creator of the fascinating Understanding Uncertainty website.
For further reading about health statistics and how the media reports them, there are lots of places to go. Ben Goldacre provides a trenchant critique in his Bad Science column; the NHS' Behind the Headlines analyses media stories on health; and Health News Review does the same thing in the US, giving each story a star rating.
And look out for more soon from the science training for journalists programme. We have an event coming up, in association with the BBC College of Journalism, early next year that will bring together a top scientist and science correspondent for a discussion and Q&A about science reporting. And there are links to relevant online resources here.
Dr Martin Griffiths is National Coordinator, Science Training for Journalists, at the Royal Statistical Society.
