Letters and authors’ reply on Potential Outcomes paper published (IJE)

Two responses have now been published to the Vandenbroucke-Broadbent-Pearce paper on Potential Outcomes in IJE (Jan 2016).

We have replied to these letters (open access).

As well as this exchange of letters, the IJE has asked for some fuller commentaries on our paper, as well as our response to these commentaries. The exchange is developing in an extremely useful way, in my view, and I look forward to being able to share the next “round”, perhaps later this year.

Our original paper is here.

 

Paper “Health as a Secondary Property” accepted by BJPS

Subject to a few final adjustments my paper “Health as a Secondary Property” has been accepted by the British Journal of Philosophy of Science.

I’m pleased because this is my first contribution to the debate in the philosophy of medicine about the nature of health. I’m also pleased because the paper is a proving ground for some ideas that I want to develop further in my book on philosophy of medicine. And of course I’m happy because BJPS is a great journal.

It may change in minor ways, but here is the abstract. Obviously I can’t post the full paper here but if you are interested in seeing a pre-print privately, please contact me.

ABSTRACT

In the literature on health, naturalism and normativism are typically characterised as espousing and rejecting, respectively, the view that health is objective and value-free. This paper points out that there are two distinct dimensions of disagreement, regarding objectivity and value-ladenness, and thus arranges naturalism and normativism as diagonal opposites on a two by two matrix of possible positions. One of the remaining quadrants is occupied by Value-Dependent Realism, holding that health facts are value-laden and objective. The remaining one, holding that they are non-objective but value-free, is unexplored. The paper endorses a view in the latter quadrant, namely the view that health is a secondary property. The paper argues that a secondary property framework provides the resources to respond to the deepest objections to a broadly Boorsean account of natural function, and so preserves the spirit, though not the letter, of that account. Treating health as a secondary property permits a naturalistic explanation of the health concept, specifically, an evolutionary explanation, in terms of the assistance such a concept might have provided to the survival and reproduction of organisms that have it. (This approach is completely distinct from evolutionary and etiological accounts of natural function.) This provides the otherwise missing explanation in Boorse’s account for the fact that function is determined with reference to contribution to goals of survival and reproduction, assessed relative to classes comprising age of sex of species, rather than some other equally natural goals or classes. 

Preview: Abstract of Inaugural, ‘Prediction and Medicine’

Having blogged earlier today about philosophy, history and medicine, I’ve settled on an altered abstract for my upcoming inaugural. It’s below.

Anyone wanting an invite but who hasn’t received one by the end of this week should feel free to contact me directly and I’ll see if I can add you to the invite list. It’s 2 August.

 

Prediction and Medicine (Abstract)

What is medicine? In the context of the contemporary Western tradition, it is easy to suppose that medicine is the process of treating a sick person’s body, or mind, so as to make it better—or something like that, suitably adapted to take care of cosmetic surgery and so forth. But even so adapted, this “curative thesis” is not satisfactory. Historian of medicine Roy Porter maintains that the position of medicine in society has had, and still has, little to do with its ability to make people better. Perhaps Western medicine is uniquely capable at curing individuals given adequate resources, but it is very far from perfection even in these terms, as philosopher Jacob Stegenga has recently argued in urging “medical nihilism”. And its efficacy at improving population health has been famously doubted by historians and epidemiologists (hygiene, nutrition, wealth and peace being more effective). When we look at non-Western and older Western medicine, we see that Western medicine is unique in another way, in proffering explanations in terms of the individual body and, perhaps, mind. Most other traditions see disease as more widely significant, of sickness in the body politic (e.g. “the state of Denmark”), displeasure of ancestors of gods, malicious forces, imbalances in the natural order, and so forth. The “curative thesis” demands that we have mostly been stupid, duped, or staggeringly hopeful, given that medicine has not until recently and locally offered more than a handful of effective cures; and it ignores the connection of medicine with cosmic matters that is characteristic of most medicine. I suggest, in this lecture, that the core medical competence is not to cure, nor to prevent, but to predict disease. The predictions expected of doctors are both actual and counterfactual: both “When will I get better?” and “What would have happened if I had not taken my medicine?”. This “predictive thesis” does a better job than the “curative thesis” at explaining why not all medicine is concerned with curative efforts, and it enjoys considerable historical support from the ancient entanglement of prophesy and medicine and from the fact that medicine thrived for centuries with almost no effective cures, and continues to thrive today in various forms that are mostly without curative efficacy, perhaps also enabling a fairer approach to alternative, traditional, and other medical practices. I also argue that it relieves medicine of the pretences of potency that generate the righteous indignation implicit in the arguments for medical nihilism. I also ask whether this descriptive thesis about the nature of medicine offers any prescriptions, or lessons, for the development of medicine.

Medicine, History, and Philosophy

On 2 August I’m delivering my inaugural at UJ. I’m developing the talk I gave at various places earlier in the year, so recycling the title (‘Prediction and Medicine’) and the abstract (below). If anyone can suggest an image for the publicity I would be very grateful–the obvious Google result of a doctor holding a crystal ball somehow does not appeal…

I’m currently trying to get my book on philosophy of medicine underway, and I’m increasingly convinced that the history of medicine must inform this discipline in a much more thorough way. Here are my initial broad brush thoughts.

First, it’s clear that the question “What is medicine?” is a really fruitful one. If you take a global view, of both time and place, you see many differences between practices, and some striking similarities. Roy Porter, my sole historical influence (and I realise I should diversify but he’s just so good), points out that most medical traditions see sickness and health, death and life as relating to humankind’s place in the cosmos. Hence the tendency to see disease as divine retribution, or the displeasure of ancestors, or malice on the part of evil spirits; and hence the connection–in Hamlet, for a European example–between sickness in the physical body and the body politic. (And, I suppose, the mind.) The modern Western tradition is unique in not seeing sickness in this way, but in understanding sickness by study of the sick body, more or less in isolation from its environment.

 

This provoked in me the thought that epidemiology is, in a way, the modern Western corollary of “our place in the universe” style explanations–that is, explanations in terms of influences, environment, and circumstance. This perhaps explains the tension that sometimes exists between medicine and epidemiology, between the biological perspective and the population perspective. Perhaps it also explains some of the tension between public health advocates, and their typical moral and political orientations, and the medical profession with their typical professional moral and political leanings.

Perhaps, even further, it shows Evidence Based Medicine in a new light. The suggestion that “bench science” should be at the bottom of the evidential hierarchy, and not leading the charge, is truly radical from a historical perspective, uniquely in the history of Western medicine. Western medicine is also uniquely successful among medical traditions, at least in its own terms: that is, measured in its the potential to cure individuals given adequate resources; the picture is far less clear if the measure is the actual improvement of population health, where, as epidemiologists have pointed out, other factors–nutrition, genetics, environmental exposures, income–have a larger effect than medical treatment per se. Nonetheless, Western medicine is uniquely successful on its own terms, and I wonder: is this attributable to the “anatomy first” approach? –and if so, does the EBM movement realise the enormity of recommending that this approach be, in effect, abandoned?

This is all massively general, of course: I did say “broad brush.”

The second thought that I can’t help be struck by, when reading history, is how much better historians are at speaking to non-historians than philosophers. I would love to be able to do this, because the questions I want my book to concern are questions many people care about and think about. Perhaps “What is medicine?” is too abstract, but sub-questions surely concern us: should I vaccinate my child? Has the doctor correctly diagnosed me? Should I take anti-depressants, see some sort of therapist, or just get out more? Am I sitting here waiting to be discharged for any good reason or is it just that it’s a Sunday and I could actually leave now? Do I drink too much, really (I know I’m above the guidelines but come on, they’re ridiculous)? What are the likely consequences of not breast feeding my child?

Philosophical discussion can help us answer these because of the gap created by conflicting medical advice. It’s not a matter of critiquing doctors; it is a matter of adjudicating between them, something that, in my experience, I have had to do almost every time we consult more than one doctor on the same matter. The fact is that there is considerable conflict in medical advice. Here is a recent example. A few days ago I took my youngest child for a round of vaccinations. The nurse said that if there was a fever later, we couldn’t give any paracetamol because the baby was too small, but should instead use a certain homeopathic suppository. This is a complete mix-up of supposedly contrary ideologies, and indeed of homeopathic method so far as I understand it. Moreover the nurse did not know that we had spent the previous week in hospital with the same little one (she had bronchiolitis) and during her stay she consumed considerable quantities of paracetamol. We accepted the suppositories, but haven’t used them (nor did we need to use paracetamol).

This is just one example; I’ve experienced numerous others, in fact in almost every matter of significance that I’ve had to consult a doctor on, with the possible exception of the removal of my appendix (and even that, according to a remark of a prominent EBMer at a conference shortly afterwards, could have been alternatively treated with high dose antibiotics according to the Best Evidence). This constant conflict between medical advice is at odds with what some commentators on medicine suggest–I mean those who are most shrill in their criticism of homeopaths, anti-vaccers, etc. (And I include EBM advocates, because they often seem to assume that the best evidence speaks for itself, with a single voice.) And that’s just within the Western medical tradition. It doesn’t begin to touch on how a young Zulu woman should direct herself when she hears voices and is told by her lecturer (me) to visit the university counselling service, and by her traditional healer that she is being called to that same profession.

All of this means that a good philosophical treatment of medicine that is accessible to people other than philosophers could be enormously useful. Bizarrely, philosophical academic writing is particularly tangled up in its own literature. It bristles with references. Historians can write papers about topics, in which the references to other historians are fairly select: the main interest is not (or need not be) what other historians have said about the topic, but the topic itself. Philosophers have trapped themselves into a new scholasticism: the interest of a topic for philosophers seems largely to lie in its relation to what other philosophers have, or have not, said about it. This is bizarre because philosophy is conceived by the non-philosopher as the dreamiest of disciplines, the most outward looking. But in its current form, it isn’t. Analytic philosophy is no better than continental in its obsession with its own texts; the difference is just that the texts analytics focus on are more recent. It is still possible to write a philosophical paper citing nothing but other philosophical papers; perhaps even desirable. I’m not saying that’s never ok, but if that is all we do, then how do we get off the ground? And more pressingly for my present topic, if that is what we are expected to do, then how can we ever write in a way that can be accessed and understood by the non-philosopher?

A lot has been made of access to the discipline in relation to class, wealth, race, gender. But aside from all those problems (and I do not belittle them), I think we have a deeper access problem. Far from being the kind of discipline that any intelligent person can engage in, with some though, we have a discipline that no outsider can meaningfully participate in or even learn much from without huge prior training, at which point they are no longer an outsider.

Broad brush, as I say… There are exceptions and qualifications, of course. Nonetheless I stand by my core claim, that philosophy has an unwarranted intellectual access problem, one that is not created by the intrinsic nature of the discipline but by the choices made among its professional practitioners about how to conduct debate and, indeed, what topics to discuss. But my hope is to break out of some of these difficulties, and I think that a book about medicine is a great opportunity to do it. Why can’t a philosophical treatment of medicine be as readable as Porter’s excellent historical treatment? I can’t think of a good answer.

How much of this I get to in the inaugural, I don’t know; the abstract for the latter is below. Perhaps I should change it and deliver a big picture discussion of the nature of philosophy… But I’m not sure I’m quite brave enough for that yet.

 

Abstract

Historian of medicine Roy Porter maintains that the position of medicine in society has had, and still has, little to do with its ability to make people better. There is a line of thinking in both history and philosophy of medicine that we might call medical nihilism (following Jacob Stegenga). This view holds that medicine is not what it is cracked up to be. But this view assumes (unlike Porter) that the purpose of medicine is indeed to cure people. In this paper I argue that the core medical competence is not to cure, nor to prevent, but to predict disease. The predictions expected of doctors are both actual and counterfactual: both “When will I get better?” and “What would have happened if I had not taken my medicine?”. This “predictive thesis” does a better job than the “curative thesis” at explaining why not all medicine is concerned with curative efforts, and it enjoys considerable historical support from the ancient entanglement of prophesy and medicine and from the fact that medicine thrived for centuries with almost no effective cures, and continues to thrive today in various non-Western and complimentary forms that are mostly without curative efficacy. I also argue that it relieves medicine of the pretences of potency that generate the anger implicit in the arguments for medical nihilism. This view also affects expectations of epidemiology, which is sometimes criticised for cataloguing predictive risk factors whose causal relation to the outcome is unclear, instead of identifying decisive interventions. Finally I ask whether this descriptive thesis about the nature of medicine offers any normative lessons for the development of medicine.

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]

Miscarriage, economic downturns and causality

There is a really interesting piece and ensuing discussion in recent American Journal of Epidemiology:

“Spontaneous Pregnancy Loss in Denmark Following Economic Downturns” http://aje.oxfordjournals.org/content/183/8/701.full?etoc

I find this interesting for a lot of reasons, including that it suggests another respect in which health and economic well-being are linked. But I am particularly curious how potential outcomes enthusiasts would respond to this sort of study, given that an economic downturn is neither a well-defined intervention nor susceptible to one.