Transcript
ADAM RUTHERFORD
A study published in the British Medical Journal observed that there are higher incidences of various cardiovascular diseases in areas significantly affected by aeroplane noise. It’s a good, small study, and they’ve tried to account for some of the confounders – the factors that might affect that result, ethnicity, sex, age, socioeconomic background, and so forth.
But the headlines did what headlines do. Ealing Today went with ‘Living under a Flight Path can Damage your Health’, and the Independent, ‘Why Living near an Airport could be Bad for your Health’. So we went to statistician Professor Kevin McConway from The Open University, and I asked him what we can really conclude from that study.
KEVIN McCONWAY
Well in a sense we can’t conclude anything for sure. I mean all they really found was that if you live in areas where there’s more noise, and if we kind of allow for various differences between those areas, the people who live in those areas, taken as a whole, are more likely to have heart disease and strokes. What we can’t conclude directly from what they did is that aircraft noise is really bad for you. In fact we can’t conclude it’s bad for you at all. We can just say there’s an indication it might well be, and we ought to look further at it which is, what they say in the paper.
ADAM RUTHERFORD
So the paper itself is fine but the reporting of nuanced findings, where do the faults come in? How does it translate from being a nuanced paper in to being dramatic headlines?
KEVIN McCONWAY
I think the problem is that it’s difficult to get a nuance conclusion in to a headline. ‘Aircraft Noise Might be Bad for you or it Might Not’, you know, it kind of doesn’t sound very good. And it’s kind of indefinite. People want certainty, and I think you have to be conscious of the process by which the newspaper headline is produced.
Now in the press release for this story which I’ve seen, it gave the ‘ifs’ and ‘buts’ to a certain extent. It said, well you know they found this relationship between noise and heart disease and strokes, but they really don’t know that that’s causal. And they reported that fairly in the press release, but then it gets in to the paper. There’s another filtering process.
ADAM RUTHERFORD
And when it gets in to the paper some of the reports and some of the headlines that we’ve heard have made one of the classic errors, which is to confuse correlation with causation. So we see a relationship in the paper between aircraft noise and an increase in cardiovascular disease, but what does that mean? It doesn’t mean that they’re causing one another.
KEVIN McCONWAY
Well it doesn’t mean for sure that they’re causing one another. A possibility is that one’s causing the other. So you can’t say, ‘Well these two things are correlated, but it isn’t the case that one’s causing the other’ because you don’t know that definitely, either. It might well be the case that aircraft noise does cause these diseases, but it might not be.