The Winton Centre for Risk and Evidence Communicationwintoncentre.maths.cam.ac.uk
What type of statistical measure is being reported?
Why is the newspaper’s headline misleading?
Susan, a journalist, wrote in her article: ‘Eating 4 portions of pizzas, pastries and processed meats every day increases risk of death by 62%’.
This number is accurate, but sounds very worrying. What would have better conveyed the magnitude of these results?
Normally, 1 in 1,000 people have a heart attack in a year. How many people have to take the drug in order to prevent one heart attack?
The study was performed in 100,000 people, randomised into groups A and B with 50,000 each. Group A had 2 cups of coffee per day and group B didn’t have any coffee at all. In group A, two people developed heart arrhythmia, whereas in group B, one person did.
Which feature of these results is the most problematic when trying to draw conclusions?
Julia, a healthcare journalist, is surprised by this and wants to investigate further, so she contacts the researchers. She finds out that premature births occur in 6% of women without type 1 diabetes.
What percentage of births would you expect to be premature in women with type 1 diabetes?
For example, a study published in 2013 explored the association between taking statins and reporting muscle pains. They reported an Odds Ratio of 1.18 - meaning that the group taking statins had 1.18 greater odds of reporting muscle pains than the group not taking statins.
In absolute figures, they found 87% of people taking statins reporting muscle pains, compared to 85% of those not taking statins.
Based on this research, a Daily Mail headline claimed that statins ‘raise risk of [muscle] problems by up to 20 per cent.’
What mistake did the journalist make?