David Spiegelhalter Quotes

Randomised trials have proved the effectiveness of some Covid treatments and saved vast numbers of lives... also showing... overblown claims about treatments... as hydroxychloroquine and , were incorrect.

In the trials that led to the vaccines... adverse events were reported by 38% of those receiving the real vaccine... 28% of those who received the control [dummy, or fake vaccine, of which some were meningitis vaccine] also reported a side-effect. ...[F]ewer than 1% reported a serious adverse event, and of these... slightly more had received the dummy than the active vaccine. ...So there was no evidence of increased risk ...

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

When epidemiologists... do studies, when they follow lots of people for years, they measure the effects of various habits, in terms of s. This is what it does to your hazard every year. So if you have a daily sausage or a bacon sandwich, this goes up by about 10%, a fixed amount... as your... annual risk. 10% increase in your annual risk of death, of not making it to your next birthday.

s are disastrous. ...Relative risks are deeply misleading. They're a manipulative form of communication. To ever say, "Oh, this doubles your risk, or increases your risk 50%," absolute No-no! They are hopeless. In some situations they can be very valuable... but in general, medical things what... should be always given... s... with and without something... Like my s... I was getting... 15%, 10 year risk: 15 out 100 people like me might expect to have a heart attack or stroke. So I... roughly halved it... only in terms of relative risk... from 15% to 7-8%. ...Being told it halved it does sound good, but if wasn't a very big number in the first place, halving it is of no interest... especially if the thing's going to give me some side-effects... if it did, it would be completely pointless... [Y]ou cannot know... whether you should do something... [Y]ou cannot trade off the benefits... [and] the harms from a medical treatment without knowing the absolute risk. You cannot do it in any rational way whatsoever. ...A lot of the communication now is using absolute risk, which is a huge improvement.

There is a way... which comes from economics and social science. It was developed by... Frank Knight, and Keynes used this... The distinction between risk and uncertainty...
[R]isk is about things... we... understand... known unknowns, to use Donald Rumsfeld's... great phrase... [something] we can put numbers on, things within... circumscribed situations... A lot of medicine is like this... repetition, a lot of data. ...[I]nsurance is like this ...We know roughly what the chances are, and we can talk about the numbers.
Uncertainty is when... we don't know the numbers, or... deeper... we don't even know... the problem... the options... the possible outcomes...

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.

This current COVID-19 virus... is a classic situation... of... an uncertainty problem, rather than a risk problem because we... don't know the parameters. We don't know... how it might spread in Great Britain. We don't know the effectiveness of the interventions that are going to be made. So... when you're making projections... over the next 6 months, there's a massive range of possibilities, up to 1/2 million deaths... from about 5... the most optimistic... [A]ny quantification, giving any probabilities would be... very ambitious...

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.

Communication is not a one-way process. It's not just telling people things. ...[T]he first rule of communication is to shut-up and... just listen... and good doctors will do that. ...Good doctors will listen and explore the person's values and concerns, and... explore to what extent... that person want[s] to be guided... to be told what to do... and that's... appropriate to want... guidance from a trusted source. ...And ...make sure ...before ...that stage, you have ...genuinely laid out the options in a way that gives it balance. You haven't tried to manipulate them... into a particular direction. ...Very difficult ...but ...a worthy objective, and... having done that, it's perfectly reasonable to... then, give advice.

[S]easonal flu—average year—kills 6,000 people in this country. Mainly old... vulnerable... frail...[etc.] So we are hit by this, year after year... epidemics... we've got to put this into perspective... [T]o an extent it is a trade-off between massive disruption... [I]f you say everyone has to stay in their home for 4 weeks... that's not just economic loss. It has a massive... health... [detriment] in terms of... mentality and fitness. Norsemen of harm will be done... so it's not just a matter of... "Minimize the number of deaths."

<nowiki>[</nowiki>s] don't have to get into fantastically complicated statistics. ...It's all just to do with proportions, that's all! It's not a skill. Well, it is a skill in how to tell a story. ...[C]linicians now—we've got some online courses that do this—can learn to do it... Getting a rough idea of magnitudes is very important, and... to avoid words like "chances" and... I'm not even that keen on "s." So I'd much rather say... Experience shows that out of 100 people who match you in these characteristics—They're not you, but would be matching—This is what we would expect to happen, about 60 of them would survive this and... 30 blah, blah, blah... Just as a descriptor, and you could draw a little picture...[etc.] So we've got these possibilities. ...We don't know which one of these you'll be, and then it's very reasonable to tune it: but in your circumstances we... think you're better... other factors... put your chances a little higher... but we can't guarantee it either way.

Misleading anecdote is someone smokes 20 a day and lives to 110, [or] who buys some tablets off the web and their cancer goes away... These are not representative... stories... [T]his is an active area of research, and it's been shown that if you present information in the way that Michael was presenting, as icon arrays, show both the good and the bad, show the totality, [it's been] shown empirically that you can make people less influenced by misleading anecdotes.

Framing is absolutely vital. ...All the work in communications is driven by the work of psychologists like Kahneman, Tversky...[etc.] The simplest one... is not always to talk about s, but to talk about s, and preferably... to give both. Our predict systems are almost always... positively framed, all in terms of survival. So we draw survival curves, not mortality curves... How long can you be without this condition. ...In a way you should give both, but ...it makes a big difference ...whether you talk about 2% mortality or 98% survival. ...2% mortality sounds rather terrifying while 98% survival sounds rather good, and we don't want to unnecessarily upset people... [W]e are all going to die ...It's 100% mortality in the end, but you want to show a decline in survival ...because it's just fairer and more likely to get people engaged rather than frighten them off immediately. ...[W]hen we ...provide an icon array that shows everybody, it shows the deaths ...patients like it. ...They like seeing out of 100 people ...in 10 years time, how many people are going to be alive ...because they have the chemotherapy now, or dead because of breast cancer...[etc.]

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.