Infinite costs wouldn't be Nice

There's been a bit of a furore over the last couple of days about a decision not to approve a drug for treating advanced bowel cancer, Avastin, on the grounds that it would not be cost-effective. This has led to a huge amount of criticism, and headlines ranging from the relatively sober to the Mail's hysterical "Betrayal of the cancer patients: Rationing watchdog accused of talking down wonder drug's power to save lives".

The decision (or guidance: in fact, the final decision has not yet been made, with the guidance subject to consultation and appeal) was made by the National Institute of Health and Clinical Excellence (Nice), which decides on the cost-effectiveness of treatments and whether they should be available to patients on the NHS. According to trial data submitted by the drug manufacturer, Roche, the drug can extend the mean lifespan of people diagnosed with advanced bowel cancer from 19.9 months on chemotherapy alone, to 21.3 months with chemotherapy and avastin. This is by no means a miracle cure or wonder drug. This is a six-week gain, but it comes at a cost: the drug costs up to £21,000 per patient.

Barbara Moss, a survivor of bowel cancer, appears in both the BBC and Guardian articles. The Guardian says:

Mrs Moss said the National Institute for Health and Clinical Excellence (Nice) had put a "value on life" after it said the price was too high for the extra benefit it gives patients

While Mrs Moss is quoted in both pieces as saying:

It seems immoral to me that, as a result of negative NICE decisions like this one, people's choice of living or dying depends on whether they can afford a drug, because it isn't available to them on the NHS.

It's difficult not to have some sympathy for this point of view. But someone has to put a "value on life" (or in fact, a thing called a Quality Adjusted Life Year, QALY). Otherwise Roche could come up with a life-saving drug that cost £1 trillion per patient, and the NHS would have to fund it because you "can't put a value on life". Ultimately, the question is not just about avastin. There is only a limited amount of money for the NHS to spend on drugs, so if avastin gets funded something else (with probably greater benefit) doesn't get funded . These are clearly not easy decisions to make, which is why we have Nice to do it in the first place.

My point here is not that Nice have necessarily got this right (I'm not qualified to judge), or even that the QALY approach is the best possible one. The point is that Nice is doing a difficult, unpopular and necessary job. Accusing them of betraying cancer patients, when what they're actually trying to do is get the greatest benefit from a limited budget, is not really helpful to anyone.

Tuesday is the wettest day of the week...?

It was a bit disappointing to get back from a week in the field in Sinai, to find my employers at the University of Manchester advertising the Manchester Science Festival with this story. Apparently, Tuesday is the wettest day of the week in Manchester.

Well, every day is rainy in Manchester. Perhaps predictably, if you look at the data this conclusion is based on, you can see that there isn't exactly an astounding difference in rainfall between different days of the week. Certainly, statistically significant differences have not been demonstrated. The research has some interesting things to say about how rainfall patterns seem to have changed over the last 30 years or so: Manchester is somehow managing to get wetter. This is consistent with warmer temperatures, as more water vapour can be moved around when temperatures are higher. This is interesting stuff, and excellent for illustrating local changes in climate for a science festival. So why emphasise that Tuesday is supposedly the wettest day of the week, when the data surely don't convincingly support that? I suppose the university press office thinks that wet Tuesdays are a more interesting story than local climate changes, but I don't think I would agree.

A quick google shows that the story has been picked up by the Express (Why Tuesday is the day you'll most likely need your umbrella) and the Telegraph (Tuesday is the rainiest day), which are clearly based around the press release. I think a better press release might have been headlined "Manchester getting rainier", which is interesting and also has the benefit of being supported by the data.

Science by press release (epic fail)

While I was messing about at the University of Google, doing some research for the thing that I've just sent to homeopathy, I came across this [pdf]. Yes, the homeopaths (in the form of the International Homeopathic Medical League and the European Committee for Homeopathy) have put together a press release, based on the study in Homeopathy by Rutten and Stolper, and the study by Ludtke and Rutten in the Journal of Clinical Epidemiology. Both studies criticise (mostly wrongly) a perfectly good meta-analysis of homeopathy from the Lancet. The headline is "New evidence for homeopathy". No question mark, no caveats. You might guess that the International Homeopathic Medical League and the European Committee for Homeopathy would not be entirely unbiased sources of information. In fact, these studies are very far from being evidence for homeopathy, as I've tried to point out (and not just me). I suppose two studies sounds better than one, but the truth is that these are essentially the same study, with extra nonsense in the part that got published in Homeopathy. The studies apply a post-hoc analysis to the data from the Lancet article, and claim to be able to produce a positive result for homeopathy if you squint at the data and stand on one leg. Then they accuse the Lancet paper of data dredging. What a laugh riot.

Unfortunately, lots of scientific studies get reported based on their press releases. This means that the people who read the reports get no sense of the flaws in the study and the caveats that should be applied to its conclusions; these come from independent scientific scrutiny of the study once it has been peer-reviewed and published. Pushing press releases on your research may be a good way to get brownie points from your university, but it's not usually a good way of fostering an improved understanding of the scientific process. To be fair, it's by no means only homeopaths and their ilk who do this, as Ben Goldacre has pointed out.

Still, the good thing about this is that a search on Google News for this release shows that, at the time of writing, it has only been picked up by a few woo-ish magazines: mainstream western news seems to have ignored this more or less completely. Maybe the press has got fed up of this particular manufactured controversy, at least for now.

Homeopathy in the Manchester Evening News

I had no idea, but it turns out that the Manchester Evening News employs a homeopath, Zoe Meachem, as a 'Health and Beauty' columnist. Here's her recent column on prevention of cystitis. In the column, she recommends a number of homeopathic remedies at a 'potency' of 30c. In a 30c remedy, the 'mother tincture' is diluted by a factor of 100, thirty times. This is a dilution factor of 1x10⁶⁰, or a 1 followed by sixty zeroes. The chance of their being any of the 'mother tincture' left after this dilution is vanishingly small. The best available evidence, i.e. meta-analyses of placebo-controlled trials, shows that homeopathy has no effect beyond placebo. In short, these remedies won't do a single thing to prevent or cure cystitis. Pity, because the other advice in the column is sensible. Drink plenty of water, and seek medical attention if you have a fever, lower back pain, blood or sediment in the urine.

Ms Meachem is registered with the Society of Homeopaths, whose code of conduct says that "No advertising may be used which expressly or implicitly claims to cure named diseases". While a comment piece in the MEN probably doesn't count as advertising, perhaps it should, especially given that the piece ends with the words "To make an appointment with Zoe call xxxx xxx xxxx".

Ms Meachem also has a BSc (hons) in Homeopathic Medicine, to which the only possible response is "You've got a degree in baloney!"

How wrong is it to speculate?

Just some thoughts that have been festering since the Hurlbert and Ling paper in Current Biology, the one that showed that women preferred pink hues when compared with men. I wrote about it, Ben Goldacre wrote about it, and I think more or less everyone with an internet connection wrote something about it somewhere.

The general gist of opinion on the article seemed to be that it was an example of bad science, because of the author's speculation that their results had some sort of evolutionary psychology explanation, perhaps that women needed to pick out red berries against a green background in the days when the men were out killing stuff and hauling it back to the cave. I would agree that the data presented in the paper don't support that interpretation. On the other hand, the authors clearly identified that hypothesis as speculative. I think it's worth asking whether speculation can have a place in scientific literature.

In my view, the answer is yes. In the case of the Hurlbert and Ling paper, data was presented showing that women prefer pink hues. The authors indulged in some speculation as to why this might be the case. It should now be the task of scientists to try and devise studies that could refute that speculation. It follows the pattern make observations, formulate hypothesis to explain observations, make more observations to test hypothesis. So I think the speculation in the paper is scientifically defensible. In this context, Kaj Sand-Jensen's famous paper on "How to write consistently boring scientific literature" is always worth a look, especially the section headed "remove most implications and every speculation". Scientific caution is generally sensible, but if taken too far it can mean that possible leads are not followed up.

The problem with that approach is the way such studies get reported in the media. As we've seen, most of the stories on the paper suggested that the authors had confirmed an evolutionary psychological explanation for gender-based differences in colour preference. In fact, they had simply showed that gender-based differences in colour preference exist. With scientists getting brownie points for media engagement, it is inevitable that the differences between results and speculation get lost.

Blue vs. pink

There's a study by Anya Hurlbert and Yazhu Ling in the latest issue of Current Biology (volume 17, No. 16, p. R623) that purports to show that women prefer the colour pink compared to men. The authors explained this as a result of hunter/gatherer era distribution of labour. Women did the gathering and thus needed to pick out red berries from a green background, while the men were out killing stuff. This was picked up widely in the media (for example, there's a Times article here). As you might imagine, it has also caused some controversy, with the Grauniad's Zoe Williams imploring us to 'Stop this idiocy now!'. Nonetheless, I don't get the impression that anyone has actually read the paper. There certainly appears to be no considered evaluation of the research methods employed in the study in Williams's diatribe. So, using my academic ninja skills, I looked up the paper and read it. I recommend this approach to any science journalists.

The research methodology of the paper seems to be sound. Essentially, the authors of the study got a group of men and a group of women, a total of 208 people. The subjects "used a mouse cursor to select, as rapidly as possible, their preferred color from each of a series of pairs of small colored rectangles presented sequentially in the center of an otherwise neutral CRT display." The results were quite striking, with women clearly having a preference for pink hues with respect to men. Interestingly, the differences for a Han Chinese sub-group were much less pronounced. Anyway, so far so good. Conclusion: Women like pink hues more than men do.

So why do women prefer pink? The authors write 'We speculate [my emphasis] that this sex difference arose from sex specific functional specializations in the evolutionary division of labour'. They go on to propose that the difference might relate to women gathering red berries, or the need for women to notice subtle changes in skin colour in 'their roles as care-givers and empathizers'. As evidence for this speculation, the authors employ something called the Bem Sex Role Inventory, showing that masculinity and femininity correlate with colour preference. What on Earth is the Bem Sex Role Inventory? It turns out that this works by asking the subject how they rate themselves against a list of 60 adjectives. 20 of the adjectives are 'desirable for men' (e.g. assertive, independent, analytical), 20 are 'desirable for women' (e.g. loyal, warm, shy) and 20 are 'gender neutral' (e.g. happy, tactful, jealous). People are asked to rate themselves for each adjective on a 7-point scale. Clearly, as scientific methodology this leaves a lot to be desired, and it seems to me that this is just testing cultural constructions of masculinity and femininity. I'm not convinced that it backs the authors speculation that innate biological factors account for sex differences in colour preference. In fact, the authors are quite careful about this, and state that 'while these differences may be innate, they may also be modulated by cultural context or individual experience. In China, red is the color of ‘good luck’, and our Chinese subpopulation gives stronger weighting for reddish colors than the British'. This doesn't seem to be reflected in any of the media stories about the research, which is what happens when you get reporting by press release. Anyway, in my opinion, the research can't distinguish between innate and cultural explanations of the observations, and the stronger preference for red hues among the Chinese subjects certainly seems to suggest that cultural factors are important.

So, what have we learned? Well, we've learned that women prefer pink hues in comparison to men. But I don't think we've learned why. So, when Williams says 'Humanity has nothing to gain from research into whether females prefer the colour pink', is she right? I don't think so. We've learned something, and for that reason alone I think the research is valuable. And if we can say something definite about the reasons for the differences found in the paper, we can say something about our society and why it works in the way it does.

Ben Goldacre tears the Observer a new arsehole

As usual, Ben Goldacre does an excellent job of deconstructing the drivelling MMR/autism piece that appeared on the front of the Absurder a couple of weeks ago. The Absurder published a 'clarification' yesterday, which somehow failed to clarify that the basic thrust of the piece was entirely wrong.

http://www.badscience.net/?p=464

UPDATE: The original story has now been removed from the Observer website. I sent them an e-mail asking what had become of it, and they said "The article was removed from the website for legal reasons. We are unable to provide a copy."

The reasons behind this are not clear, but it seems likely that legal action has been launched by Dr. Fiona Scott, who was described in the original piece as believing that the MMR jab might be partly responsible for a purported rise in autistic spectrum disorders. Dr. Scott says she believes no such thing, was never contacted by the Observer, and her attempts to point this out have fallen on deaf ears.

This would all be to the good, and Dr. Scott does seem to have been treated particularly badly. But it seems unlikely that the Observer will have to take any action to correct its basic misunderstanding of an unpublished report, which has the potential to do further damage to the public understanding of an issue that is already surrounded by misinformation.