David Spiegelhalter Quotes

What we use in the book... are ways which we think might... provide gripping narratives, and yet provide a realistic way of communicating small risks...

[W]hen... there have been 30 "thromboembolic events" after around 5m vaccinations, the crucial question... is: how many would be expected anyway, in the normal run..?

[I]n medicine... ... not manipulation or coercion, is when... as a doctor or... authority, you genuinely believe that this action is in the person's best interests, but they don't... want to do it. ...How do you make that an ethical persuasion? It's based on... two things, first... respecting the autonomy of the individuals, that they can refuse... no matter what, respect their ability to choose... the other thing is your authenticity, your integrity, that... you are doing this on behalf of that individual, for their best interest; not... to keep your clinic numbers up or to stop this person being a nuisance...[etc.]

Psychologists got hold of this lovely idea of why we're trying to do it. I don't care what people do, so I'm not trying to change what they do, particularly. ...It would be nice if they could remember it... get the gist of something... learn something, but I don't even care too much about that. Psychologists have got this great scheme of what, perhaps, we're really trying to do, which is trying to breed some immunity to misleading anecdote, which is... the fact that we're so influenced by idiotic stories we hear on the web, or from our friends and neighbors.

The most serious problem is anaphylactic reactions, and the advice is not to inject anyone with a previous history of allergic reactions to either a prior [vaccine] dose... or its ingredients.

So far, these vaccines have shown themselves to be extraordinarily safe.

Life-expectancy reduced by 1 year = about 30 minutes off your life expectancy for each day with the habit = 1

These s that epidemiologists report, as Michael has so ably shown, tend to get... badly reported in the newspapers. So this... in the ... "Less Meat, More Veg is the Secret for Longer Life" which... probably could well be the case, but the way they report it... They said that if we cut down the amount of red meat... 10% of all deaths would be avoided. ...So 10% of us will live forever eating nuts. This is not true. ...[T]hey're talking about relative risk, but they don't understand.

This was discovered by Gompertz in 1825. There's something about our bodies, the way that we age, that means that every year our chance of dying increases by the same amount, 9%.

It’s a common human tendency to attribute a causal effect between different events, even when there isn’t one present...

s are very valuable in... low probability, high impact events. Every time you cross the road there is a low probability and high impact that you're going to get run over. ...You take extra precautions to reduce... very small risk to... even smaller. ...[O]n an absolute risk scale, you [might] say, "Oh, I'm not going to bother... It's not worth doing..." but... by making that low risk even smaller, it's... valid... [P]eople discovered this... doing earthquake predictions... [T]he absolute risk... it's always low. They're very unpredictable... but telling people it's 10 times normal, or 100 times normal, people will act... appropriately. ...They won't panic. They won't rush away. ...[I]n Italy ...they ...sleep outside for a bit. ...So in certain circumstances relative risk can be very valuable... [U]sing both in... situations... with very small risks.., where... consequences are... severe... [and] the cost of the intervention, the action, is... minimal. Taking a bit more precautions, being a bit more careful... not putting a big investment into making a very small risk even smaller.... not walking under ladders... a low-cost change in your behavior to make a small risk even smaller... [A]bsolute risks really don't deal well with that, because you're talking 0.000...

We find it very difficult to deal with... low numbers, one in a million, one in a billion... Once I have to start counting the zeros, all intuition and feeling goes. So it's hopeless, and of course we're bad at it. Why should we be good at doing that sort of thing? ...[I]t's more and more reported that people will use this expected frequency format, where instead of talking about... .03 per person year... What does that mean, for heaven's sakes. It's absolutely ridiculous scientific language for something. No, what you say is, out of 100 people... we would expect 3 for this to happen each year. ...You talk about a specific group of people, which you can... draw a... picture of... and that helps enormously. You... want to bring things to... whole numbers, small numbers, preferably between 1 and 100, or between 1 and 50... magnitudes that people have got a feeling for, and... no decimal places, no multiple zeros. You've got to get rid of all of that. You've got to get things to units people can understand, preferably on a scale of 1 to 10.

[W]e tend to think... of something that's going to happen... soon, or is well understood as risk, but if we're talking about what will happen in the world in ten years time. Who's going to start putting chances on this. You'd be... deluded... There's much... deeper uncertainty or... radical uncertainty...

[S]omeone is diagnosed with autism after receiving the , so people assume a causal connection – even when there isn’t one.

If you go to the English Parachuting Association web site... you find this lovely Excel spreadsheet which has got all the deaths... [F]or the last 20 years, 4.6 million jumps, 48 deaths... or 10 in a million. On average, with going up in a plane... I thought there's around 7 or 10 in a million chances of me dying. There's 50 million people in England and Wales... Every day 50 of them have accidental or violent deaths... not to do with their health. So a couple are murdered a day, a few are run over, some people fall off ladders, etc... So that's 1 in a million... Our daily dose of acute risk is a [a 1 in a million chance of dying]. So jumping out of a plane is only about a week's worth. ...[I]n terms of overall mortality... at my age, 59, it's 7,000 micromorts a year in terms of my chances of dying. So an extra 7 or 10 on top of that... [I]t's worthwhile doing... it once....So I did it [parachuted], and I survived.