David Spiegelhalter Quotes

<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.

The worst... medical care would be just say, "Oh well, it's completely up to you. I'm not going to give you any advice." Well... you're the guy who knows... [the] supposed... expert. ...I want your advice. ...[T]his is an invaluable process which I hope all medical students have been taught. How to engage... It's not . ...Paternalism is ...immediately saying, "...I think you should do this," without really allowing that person a full autonomy to choose.

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.

[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.]

When it comes to trying to prevent you endangering other people, I don't see anything wrong with persuasion. ...[Y]ou shouldn't be... [endangering people] and you should be trying to be persuaded, if not forced... I get quite Stalinist on these things because... it's so irresponsible for some people to endanger the health of others. If they wanted to make their own decision that only affects them, it's very different, and I wouldn't want to persuade anyone...

When it comes to vaccines and infectious diseases, nobody is an individual... [With] [i]nfectious diseases... measles when it comes to vaccine decisions, or COVID-19 when it comes to taking precautions, we're not individuals. We are members of society, and there's no... "optimize your individual situation." You have... an absolute responsibility... to protect the people around you, particularly the vulnerable... [T]hat's why... people who avoid vaccinating their kids is outrageous and irresponsible... they are endangering weaker kids who might not be able to have the vaccines because their immune system is compromised or for some [other] reason... [S]imilarly, if young... healthy people... not... harmed by the virus, go around being irresponsible, they are endangering the lives of older people surrounding them, in particular, their own family.

We know from studying and going... back to Geoffrey Rose's idea that the biggest impact on public health... is not by picking out the real high-risk people and maybe stopping them drinking. It's by reducing the exposure of the vast mass of people at intermediate risk. So... the biggest impact on public health would be if everybody drank a little bit less... But the problem... is the Rose paradox... the very people you want to change the behavior [of] are the ones who don't see why they should change their behavior, because the impact is minimal. They won't notice the benefits. You're asking them to give up something they enjoy for the benefit... they will... never notice... [I]t's only noticeable when... multiplied... ten million times./* Understanding Risk (Mar 24, 2020) */Ref: "a large number of people at a small risk may give rise to more cases of disease than the small number who are at

[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."

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...

[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...

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...

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.

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.

Probability was only invented a few hundred years ago. It's not a natural way to think at all. It's extremely difficult and complex. Anything that can help people do it, is of benefit.

[W]e can compare hang gliding... taking heroin... health treatments, with standing next to Hiroshima. We're deliberately... using these numbers to tell uncomfortable stories.