‘Risk is risky’, it says in Note 12 in Number Hygiene our guide to journalists on how to write up stats.
Unsuspecting readers too often get waylaid by headlines screaming things like ‘eating bacon increases bowel cancer by 20 per cent’ …when what we know is that consuming a large extra amount of the offending ham produces a slight increase in the absolute risk of contracting the disease.
But journalists won’t mend their ways. The Lancet has just published an interesting and scientifically reliable study showing that children receiveing large doses of radiation from CT scans – three or more scans — have an increased risk of cancer in later life. The excellent NHS Choices website gives full details of the research and responses.
They, typically, are lurid. The tabloids saw the figure three in the press release on the research and they were away – claiming the cancer risk is tripled. Even the Independent joined the bandwagon. By contrast the Guardian offers a case study in how to report research findings accurately.
What they show is that the risk of developing a brain tumour or leukaemia following childhood CT scans remains small. If 10,000 children under the age of 10 each received one CT scan, this would be associated in a single additional patient developing a brain tumour or leukaemia over the next 10 years: a 0.01% increase in case.