Archive for November 8th, 2009

Kneed in the Nutts – or shot in the foot?

November 8, 2009

In which Dr Aust has a think about risk, and wishes politicians would stop trying to have it both ways.

The big science story in the UK these past couple of week has been the sacking of Professor David Nutt, the Chairman of the Advisory Council on the Misuse of Drugs (ACMD). The blogosphere has been aflame with commentary. My favourite comment so far, which most readers here will probably have read already, is David Colquhoun’s brilliantly pithy summing up over at the BMJ:

“Remember George W Bush? For him it was simple. If a scientist told him an inconvenient truth, the messenger was fired, and someone more compliant got the job. In every area from global warming to the existence of weapons of mass destruction he chose to base policy on fantasy and wishful thinking. It seems that the UK home secretary, Alan Johnson, has something in common with Bush. When the Advisory Council on the Misuse of Drugs (ACMD) said something he didn’t like, its chairman, David Nutt, got fired….”

British Medical Journal online

Alan Johnson and other members of the Government, notably including Prime Minister Gordon Brown, have tried to spin the story as Prof Nutt “stepping into the political arena”. Governments, they argue, have to consider things “in the round”, in Gordon Brown’s phrase (i.e. there is more to it than just the evidence the scientists have sifted, assessed, and synthesised).

Alan Johnson put it like this:

“As for [Prof Nutt’s] comments about horse riding being more dangerous than ecstasy… it is of course a political rather than a scientific point. There are not many kids in my constituency in danger of falling off a horse – there are thousands at risk of being sucked into a world of hopeless despair through drug addiction.”

Now, the assertion that this statistical comparison is “a political rather than a scientific point” is a rather politician-ly piece of rhetoric. First off, the comparison he is referring to was published in an article in a scientific journal. It was only when the newspapers got hold of it, and that it then came to the attention of politicians, that it caused such a furore, with both sides of the House of Commons getting on their hind legs to compete to see who could denounce the “nutty Professor”, and the evils of drug use, in more ringing terms.

One of my favourite medical bloggers, the ruminative and understated hospital consultant Dr Grumble, has also been covering the story. He does not agree with Johnson, and points out that analogies for risks are actually an important way of communicating risk.

“[Alan Johnson] claims, it seems, to have sacked Professor Nutt because he compared the risk of drugs with the risk of riding a horse. He says this is ‘of course’ a political point. Dr Grumble doesn’t agree. Even as a scientist you need a yardstick rather than a figure to put risk on a scale which can be understood. This is particularly true if you need to express levels of risk to politicians or the public. But the concept is useful for scientists too. In the assessment of risk this is not unusual. It was not something that was calculated to embarrass Alan Johnson. It was just an aid to understanding.

Professor Nutt chose horse riding because it happens to be very risky. Dr Grumble knew this. He has seen the consequences. Yet many parents – though maybe not in Alan Johnson’s constituency – might encourage their children to take up horse riding. Few would do the same when it came to drugs. Yet the risk for horse riding is much greater. Both are probably done for some sort of excitement. One is a fulfilling activity the other probably is not. It doesn’t matter. It is just a yardstick.

We need such yardsticks. Parents need to grasp how likely it is for their child to be murdered in comparison to being run over on the road. It’s important. Do we need to invest in looking out for child murderers or slowing the traffic? Those are the issues.

The trouble, of course (!) is the Daily Mail. It is more likely to fill its pages with stories of horrific child murders than car accidents. The Mail is unlikely to report many of the deaths related to alcohol and tobacco. There are just too many. The differential reporting of drug-related deaths in the press is something that David Nutt has pointed out. The likelihood of the press reporting a drug-related death depends on the drug. Some drugs, it seems, are more newsworthy than others. But the consequence is that the public’s perception of risk is warped. It is important to point this out. The public needs to grasp the real risk and not the risk they perceive from reading newspapers. So do politicians.”

Does Alan Johnson keep a gun?

Indeed. Back in Mrs Dr Aust’s days in anaesthesia, the number one question she used to get asked by patients when she met them on the morning of their operation was:

“Am I going to wake up from this doc? Is it dangerous, this anaesthetic?”

Let’s assume the patient was a physically fit person having a routine and fairly brief anaesthetic for an uncomplicated minor surgical procedure. In such cases, one of her preferred replies was:

“Well, if you came here this morning in a car, then you’ve already got away with doing something more dangerous than the anaesthetic I’m going to be giving you.”

She did not quote a numerical risk figure, because the chance that an anxious patient would have taken in a “one in however many thousand” risk figure, and then processed it cognitively, and actually felt reassured, was basically nil.

The analogy, however, with it’s element of risk comparison, did the job nicely.

So I don’t think Johnson’s points about Nutt’s analogy stand up. As Dr Grumble alludes to, the point Nutt was really making was that people have views of the risks associated with different activities – and especially the use of different drugs – which bear no relation to the real risks, and that this is unhelpful in making sensible policy.

Professors, politicians and the real world – just who is out of touch?

Which in turn suggest another of the implications directed at Nutt by Johnson and others in the political arena is incorrect; the idea that Nutt and other “ivory tower academics” do not understand that real world decisions – like those taken by politicians – have to factor in things other than simply the scientific case.

This idea, that there is more to political decisions than simply the facts, reminds me of a famous story about “risk perception”. The version that I know appears in Michael O’Donnell’s book Medicine’s Strangest Cases, and concerns the Swedes and the Lapland satellite evacuation.

The story was that a satellite in a decaying orbit was predicted to crash-land in an remote area of Lapland that was virtually unpopulated save for a few nomadic reindeer-herders. The Swedish Govt. offered to helicopter airlift the reindeer herders out of the area, at significant cost to the Swedish taxpayer.

Hermann Bondi, a famous British mathematician and – funnily enough – Government science adviser, who heard the story, crunched the numbers and confirmed that the probability of any reindeer herder who stayed put having the satellite land on them was several orders of magnitude less than the chance they would be killed in a helicopter crash on a routine helicopter flight.

So the Swedish Govt’s decision was daft.

Well, that depends.

Purely on the statistics, it was a wholly illogical decision. But Bondi pointed out that the Swedish Govt had undoubtedly factored in that if they didn’t offer to evacuate people, and the satellite then landed on someone and killed them, then the headlines would scream

“Heartless and negligent Govt leaves reindeer herders to die”.

While if the chopper crashed, the headline would be

“Tragic helicopter crash kills herders”

– and the Govt. would be off the hook.

So Governments weigh more than just the basic facts. But is Professor Nutt really out of touch with these realities of decision-making in Government when it comes to drug policy, as the politicians have implied?

Well, some idea of the Prof’s thinking can be gleaned from the published version of his recent lecture. This is, in fact, precisely the lecture, delivered to the Centre for Crime and Justice Studies at King’s College London, that caused the recent flare-up that led to Nutt’s sacking. The full version of the lecture can be read here.

Here is an extract:

Drug policy

Formulating policy in relation to drugs is obviously
quite a difficult thing to do. I comment on it, as I
always have, from the perspective of a psychiatrist
who is interested in drugs and drugs and the brain.
In many ways, that’s how the Advisory Council on
the Misuse of Drugs (ACMD) covers it. We have a
range of expertise on the Council; we’re very strong
in terms of chemistry and pharmacology, and
psychology; and we have a definite knowledge,
interest and responsibility to look at social harms as
well. We provide one arm of the policy formulating
perspective. In addition, there are a number of other
agencies, organisations and individuals who
contribute to policy formation…

There are also international partners – we
have signed up to international treaties – which
determine that, in essence, the UK follows United
Nations policy on drugs. This can be quite a tough
constraining influence on how countries regulate

Then, of course, there are other factors feeding into
political decisions about drugs: what the general
public thinks (or is thought to think); and then there’s
the media….

(colour added for emphasis)

The full article is well worth a read. It is one of the more accessible and intelligent explorations of the issues in drug policy that I have read, and certainly far more informative than anything you will read in even the broadsheet newspapers in the UK. The main theme explored is whether drug classification, and the attendant penalties for illegal use, should be linked to the actual harm caused by use of the drug, and the ways this harm can be assessed. What comes across in it is that Nutt is in no way “naive” about the political process that goes into the decisions of drug classification. What he largely argues for is more sophisticated approaches to educating the public about the relative riskiness of different activities, both legal and illegal.

Advisers and “advisers”

What about the final argument – that politicians should have advisers that speak only in private, and who in public never disagree with the Government line?

Are politicians entitled to expect advisers to keep quiet?

The answer, I would say, is that it depends on the type of adviser. There are advisers, and advisers.

Most relevantly, some advisers are civil servants, paid by the public purse, including some “personal” advisers.

Others, like Prof Nutt, are independent experts.

Much of the discussion on the Nutt case in the newspapers and in parliament has failed to make this distinction clear. And as David Colquhoun, among others, has noted, Alan Johnson has led the way in promoting this confusion.

One correspondent at Dr Grumble’s blog defended Alan Johnson in terms rather similar to those Johnson himself used :

“Prof Nutt was asked to leave because he crossed the boundary between advising the government AND making views against goverment policy public”

Compare Alan Johnson, quoted in the Guardian:

“[Professor Nutt] was asked to go because he cannot be both a government adviser and a campaigner against government policy. This principle is well understood and long established.”

I was moved to pen something in response, which I will re-post here from Dr Grumble’s blog:

“Nutt is not a Government adviser in the usual sense that an “adviser” is a paid employee, like the Chief Scientific Adviser and other civil servants. Nutt is an academic, paid nothing, and appointed to a statutory body whose job (clearly set out in their terms of reference) is to tell the Govt what the scientific evidence actually says. Not what the government wants to hear. Read David Colquhoun’s spot-on summary in the BMJ.

Alan Johnson sacked Nutt for what he said in an academic lecture whose content was not overtly critical of Govt. Furthermore, since giving the lecture was part of Nutt’s day job (the one he is actually paid to do), what he says in it is in no way part of the Govt’s purview. It is his considered opinion as an expert.

The anomaly is that Johnson is able to sack Nutt from this post. The body should be wholly independent, with the Chair appointed from within the Committee.

If Johnson were then to want to hire a “private office” drug policy adviser who was an “on message” paid yes man, so be it. At least that would be the politicians being honest about what they really wanted.

However, said hypothetical person, if what they advised was contrary to all the expert opinion, might have rather little credibility out in the world of drug policy – a bit like the way Lord Adonis was regarded by virtually all in education when he ran education policy from his role as Tony Blair’s “Education Special Adviser.”

The problem is that the politicians want to be able to say “We are acting directly in accordance with the evidence and expert opinion” precisely when they aren’t. You can hardly blame the independent experts for pointing out when the politicians engage in this kind of routine (for a politician) but rather blatant dishonesty.”

And, in the final analysis, that is what really disappoints me. I have hitherto had a fair amount of respect for Alan Johnson, one of the sadly rare MPs who have any experience of the world beyond the circumscribed horizons of the British political class. He always struck me as fairly unprententious, and not a hypocrite.

Until now.

Because that is what it is – hypocrisy. Which came from both sides of the House of Commons, with the cant, windbaggery, and general posturing for the cameras and the Daily Mail broken only by the pertinent words of the “MP for Science and Evidence”, Dr Evan Harris:

“With every personal attack on David Nutt, and every piece of cod science [Alan Johnson has] produced, the home secretary deepens the crisis of mistrust between scientists and the government.”


Experts, including scientists, can cope with politicians disregarding what they say – partly because it is par for the course.

Disregarding what the experts say, AND telling them they are obligated not to point out that this is what the Government has done – all while the politicians insist smugly that they have “evidence based policies” – is something else.