Epidemiology and Law: two publications

Recently published:

Forensic Epidemiology, Principles and Practice. 2016. Freeman M and Zeegers M (eds). Eslevier. http://store.elsevier.com/Forensic-Epidemiology/isbn-9780124046443/

(I have a paper on causation and epidemiology.)

Also, previously online but now in print:

‘Tobacco and Epidemiology in Korea: old tricks, new answers?’ Broadbent A and Hwang Ss. Journal of Epidemiology and Community Health 2016;70:527-528. http://jech.bmj.com/content/70/6/527.full doi:10.1136/jech-2015-206567 [open access]

Advertisements

Paper – Tobacco in Korea

Alex Broadbent and Seung-sik Hwang, 2016. ‘Tobacco and epidemiology in Korea: old tricks, new answers?’ Journal of Epidemiology and Community Health doi:10.1136/jech-2015-206567.

Now available online first, open access.

http://jech.bmj.com/content/early/2016/01/14/jech-2015-206567.full

For those at the recent CauseHealth workshop N=1, this relates to the same key topic (viz. the application of population evidence to an individual), but in the legal rather than clinical context.

 

Tobacco and epidemiology in Korea: old tricks, new answers?

Today I participated in a seminar hosted by the National Health Insurance Service (NHIS) of Korea, which is roughly the equivalent of the NHS in the UK, although the health systems differ. The seminar concerned a recent lawsuit in which tobacco companies were sued by the NHIS for the costs of treating lung cancer patients. The suit is part of a larger drive to get a grip on smoking in Korea, where over 40% of males smoke, and a packet of 20 cigarettes costs 4500 Korean Won (about USD 4.10 or UKP 2.80). The NHIS recently suffered a blow at the Supreme Court, where the ruling was somewhat luke-warm about a causal link between smoking and lung cancer in general, and moreover argued that such a link would anyway fail to prove anything about the two specific plaintiffs in the case at hand.

I was struck by the familiarity of some of the arguments that are apparently being used by the tobacco companies. For example, the Supreme Court has been convinced that diseases come in two kinds, specific and non-specific, and that since lung-cancer is a non-specific disease, it is wrong to seek to apply measures of attributability (excess/attributable fraction, population excess/attributable fraction) at all.

This is reminiscent of the use of non-specificity in the 1950s, when it was seen as a problem for the causal hypothesis that smoking causes lung cancer. It also gives rise to a strategy which is legally sound but dubious from a public health perspective, namely, first going for lung cancer, and leaving other health-risks of smoking for later. This is legally sound because lung cancer exhibits the highest relative risk of the smoking-related diseases, and perhaps it is good PR too because cancer of any kind catches the imagination. But the health burden of lung cancer is low, even in a population where smoking is relatively prevalent, since lung cancer is a rare disease even among smokers.

The health burden of heart disease, at the other end of the spectrum, is very large, and even though smoking less than doubles this risk (RR about 1.7), the base rate of heart disease is so high that this amounts to a very significant public health problem. I do not know what the right response to this complex of problems is: clearly, high-profile court cases are have an impact that extends far beyond their outcome, and also the reason that people stop smoking, or accept legislation, need not be an accurate reflection of the true risks in order for those risks to be mitigated. (If you stop smoking to avoid lung cancer, you also avoid heart disease, which is a much better reason to stop smoking from the perspective of a rational individual motivated to avoid fatal disease.) Nonetheless I am struck by the way that legal and health policy objectives interact here.

I was also interested to hear that the case of McTear was a significant blow to the Korean case because of its findings about causality, which indeed are exactly those of the Korean case. That case is not well regarded in the UK, and not authoritative (being first instance), so it is interesting – and unfortunate – that it has had an effect here.

The event was an extremely good-spirited affair, and the other speakers had some interesting things to say. My book, in Korean, received a significant plug, not least, I suspect, because the audience not understanding much of my talk, were repeatedly referred to it for more detail. The most shocking thing about the event was to hear the same obfuscatory strategies that are now history in Europe and America being used, to good effect, by the very same companies in this part of the world. It is one thing to defend a case on grounds that one believes, but there is not anyone who still reasonably believes that smoking does not cause lung cancer, which seems to be the initial burden that plaintiffs in this sort of case need to prove. It is a bit like being asked to begin your case against a scaffolder who dropped a metal bar on your head with a proof of the law of gravity, and then being asked to prove that the general evidence concerning gravity proves that gravity was the cause in this particular case, given that not all downward motions are caused by gravity. – Not exactly like that, of course, but not exactly unlike, either.

On the positive side, I am hoping that a clear explanation of the reasoning behind the PC Inequality that I favour might help with the next stage of the case, although I am unclear what that stage might be.

Musings on laws of nature

I am always puzzled by philosophical talk of laws of nature. The terms “law”, “govern”, and so forth amount to an extended metaphor drawn from human affairs, and thoroughly unnatural ones at that. It is a recurrent philosophical mistake to suppose that the most fundamental thing about the universe can only be treated with philosophical precision through a human metaphor. Without “laws”, and the corresponding but evidently false idea that it is possible to break them, contemporary metaphysics would look quite different. If you ask a philosopher whether it is possible to walk through a wall, she will say “Yes”, because only the laws “prohibit” it – even though everyone knows you can’t walk through a wall.