David Nutt: FactCheck readers respond
Updated on 13 November 2009
The FactCheck mailbox bulged with emails about the sacking of government drugs adviser Professor David Nutt. A selection of your views are below.
"Your treatment of the horseriding vs risks of taking MDMA (ecstasy) has misrepresented the risks I believe.
"You correctly identify that taking MDMA causes roughly three times as many deaths per year as horseriding, but you don't seem to correct for the number of people taking part, or how frequently they do so. In other words you don't attempt to estimate the number of exposures to the risk in question.
"For example, one might find that drunken snake charming only causes one death a year, but that doesn't necessarily mean it is less risky than horseriding. Particularly if only one person attempted it.
"Clearly this is a tricky area, but simply indicating the number of deaths, with no reference to the number of exposures to the risk is not really fact checking, now, is it?
"Reading the article in Journal of Psychopharmacology, it looks like Professor Nutt has attempted to do this, and finds that ecstasy results in one case of acute harm per 10,000 exposures, versus one in 350 for horseriding.
"Now, there may be problems with his estimate for the number of exposures, but you need to address those directly not just quote meaningless comparisons of numbers with no context and call it fact checking."
Ben
"Your analysis talks of the deaths due to these two causes but your analysis itself is open to question:
"1. The actual number of deaths caused by cannabis has been (accidentally) omitted from FactCheck.
"2. Even if the figure had been included, it is vital also to include the number of people engaged in each activity in order to arrive at deaths as a percentage of the total numbers involved. To take a ridiculous example: if only twelve people in the country rode horses then ten deaths makes horseriding pretty dangerous whereas we know that it isn't so.
"Incidentally, Alan Johnson's remark that he doesn't have many horse riders in his constituency is totally irrelevant and presumably was mentioned in order to somehow ridicule the professor. It is more likely to have the opposite effect."
Roger Bater
"We have to appreciate that politics is the final arbiter of our lives. If the experts believe that their knowledge is not being adhered to then they have to go into the political field. This is what the scientist did. He then has to face the political consequences of his actions. Alan Johnson was perfectly entitled to sack him."
C.E. Metcalf
"I equate political activity with party political activity. Pointing out that what a home secretary says is at odds with the facts is not political unless it is in the midst of a party political argument.
"Since the Conservatives also support the reclassification of cannabis as class B there was no argument between the two main parties. Hence what Prof Nutt said was in no way getting involved in politics. Also if the home secretary is promulgating propaganda which ignores the facts, surely the scientific advisers have a duty to draw people's attention to the facts.
"The Prime Minister also expressed the view that cannabis should be reclassified before referring the issue back to the advisory committee to reconsider. If the advisers should not involve themselves in party politics then surely the government should not be trying to influence the outcome of the advisers' review of the latest evidence.
"When comparing the dangers of ecstasy and horseriding, you need to allow for their frequency of usage. In his paper Prof Nutt compares the acute harm events of one with the other but per episode (1 per 10,000 for ecstasy and 1 per 350 for horseriding).
"You will tell from the above points that my view is that sacking Prof Nutt is not justified on the evidence. However, it is even less justified when considering the likely disruptive consequences on all sources of government advice from the science community."
David Evershed BSc(Eng) PhD MIET FCMA
"Following your publication about the feedback you have received, another point to qualify the risk of death rates those responding have discussed:
"The feedback comments are correct in that it is only meaningful to look at number of incidents in relation to the numbers of those undertaking the activity i.e. to look at rates rather than number of deaths.
"However, the picture is more complex as we are not only concerned about deaths but about the wide range of potential injury. If a million people do something and one person dies, but 999,998 suffer injury, then it might be classed a risky activity. But then we also have to look at the consequences of the range of injuries (e.g. most people doing carpentry have got splinters but that 100 per cent rate would not in itself make carpentry a dangerous activity).
"We need some way to balance the risks of an outcome against the consequences of different outcomes all in relation to the numbers and frequency of participation.
"This level of complexity is why it is essential that the analysis be undertaken by experienced professionals taking input from a wide range of disciplines e.g. as the committee concerned does.
"The complexity of the necessary analysis makes "gut feel" decisions worse than dangerous. After the experts have carried out their analysis they are in a position to advise based on the situation. A politician cannot have any justification to then ignore that advice based on "knowing better".
"A politician is invariable less experienced (compare the accumulated years of relevant experience across the committee concerned against Alan Johnson's mostly irrelevant and limited experience). A politician invariable cannot dedicate the time to a decent assessment of the situation nor the advice. So how can a politician make a "better" decision in such cases.
"That our inexperienced and busy politicians feel they can "do better" than qualified, experienced experts with time to investigate is worrying in that they are cannot be making best decisions."
Simon
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