The risks of war and peace

As of the 23rd May 2022 this website is archived and will receive no further updates.

was produced by the Winton programme for the public understanding of risk based in the Statistical Laboratory in the University of Cambridge. The aim was to help improve the way that uncertainty and risk are discussed in society, and show how probability and statistics can be both useful and entertaining.

Many of the animations were produced using Flash and will no longer work.

Who is exposed to the greater lethal risk: a member of the UK forces serving in Afghanistan, or an average patient spending the night in an English hospital? Of course the question can’t be answered exactly: it all depends on who we mean and how we measure risk. But statistics can give us a ball-park figure that may be surprising.

Let’s take Afghanistan first. Tragically, UK forces suffered 44 deaths in the 20 week period up to 21st February, with around 9,500 personnel serving each day. A 1-in-a-million chance of death is known as a micromort, and so that’s an average of 33 micromorts every day for every serviceman and woman – that’s around the risk of a motorbike ride from London to Manchester. Of course the word ‘average’ is crucial as front-line troops were exposed to considerably greater risk than this. They fully deserve our respect.

What about going into hospital? Each day in England around 135,000 people occupy a hospital bed and inevitably some of these die of their illness. But not all these deaths are unavoidable: in the year up to June 2009, 3735 deaths due to lapses in safety were reported to the National Patient Safety Agency, and the true number is suspected to be substantially higher. This is about 10 a day, which means an average risk of around 1 in 14,000, assuming few of these avoidable deaths happened to out-patients. So staying in hospital for a day exposes people, on average, to at least 70 micromorts. This is equivalent to the average risk of riding 420 miles on a motorbike, say between London and Edinburgh. The conclusion: hospitals are high-risk places.

It would be ridiculous and insensitive to say that staying in hospital is twice as dangerous as serving in Afghanistan - nobody chooses between the two options, these are different people in different circumstances, and averages have limited relevance. But getting an idea of the size of the risks is important even if it means making the sort of comparisons, say between taking ecstasy and going horse-riding, that got Professor Nutt into such trouble.

I will be talking about the risks we face in daily life at the Cheltenham Science Festival on Saturday. I will also be discussing the risks of decadent drugs with David Nutt.



It was interesting to hear the talk on Risk at Cheltenham. It certainly made me think. One thought was: is it possible to measure the mort spend rate when doing nothing in particular, in other words, the mort rate used achieved just simply by getting older. This sort of "background mort radiation" (pervading the whole of life, following the "Big Birth"), is hard to specify, never mind calculate. Perhaps it's zero, since death is always attributable to something which has its own mort rate. But the hospital example is interesting. I think the figure for an overnight stay was something like 70 morts. How many morts is just staying in bed at home (presuming there is no strong need to go to hospital that night)? Shouldn't we be looking at the mort difference in making our judgements rather than an absolute mort value? I also would like to propose a new concept: the Megamort - i.e certain death !?