Friday, March 05, 2010

Homeopathy as Misdirection

This is just a brief observation about the activism, both for and against homeopathy, that surrounded the Evidence Check. As was ruled by the check itself there is no robust evidence for the efficacy of homeopathy. It has been shown in randomised placebo controlled trials that it is no better than a placebo. So certain are many that the implausible mechanic of water and sugar-pill memory can in no way lead to any clinical benefit that they feel it unethical to undertake further research into it. The pro-homeopathy lobby might believe otherwise, but when Robert Wilson, the Chairman of the British Association of Homeopathic Manufacturers, bemoans the lack of large sample trials, and in almost the same breath volunteers what really ought to be his best piece of evidence for homeopathy and chooses a trial with a small sample size, he neatly sums up the state of play, and the relationship with evidence that most proponents of the magic water seem to have. Weak clinical evidence is waved about, strong clinical evidence against homeopathy is ignored, and if all else fails they decide that homeopathy is so special that it "defeats" science. This last argument has always puzzled me, as it consitutes an open admission that the effects of homeopathy are so fickle that you can't put any amount of faith in it.

But here's the rub. It's great fun to discuss tipping a thimble full of arsenic into the Atlantic and giving it a stir. Homeopathy is an irresistible lure to skeptics because: it turns out a lot of people don't realise what homeopathy actually is; the physics is simple to demonstrate and involves silly big numbers; it's an easy thing to compare its trials with those of mainstream medicines. I'd say this is much of the thinking behind the overdose stunt. It's purpose wasn't really to prove to people that homeopathy doesn't work, because an overdose doesn't make sense in homeopathy, irrespective of the confusing mixed messages its packaging and proponents give out. It's purpose was twofold: to demonstrate to people who don't yet know that homeopathy pills are empty, and also to have fun doing it. I'm not saying the first purpose is not important, it is. I'm not saying the second purpose is inappropriate, ridiculous beliefs are open to ridicule. However, something a little strange happened after the report was published, and is crystalised by a number of tweets and a blog post by Bruce Hood.

Hood suggests that one of the possible implications of the NHS withdrawing the supply of homeopathic remedies is that people will undergo long and fruitless investigations in order to determine what is wrong with them (homeopathy canard: we cure the whole person, what are your symptoms) and these investigations will end up costing the NHS more than providing sugar pills. I'm not sure I entirely agree with Hood, though it's worth noting that if reports are to be believed, I suspect the evidence check itself cost more than a year of NHS homeopathy. Hood is no supporter of the homeopathic hypothesis by any means, but is more interested than many are willing to be with the implications of restricting access to placebo-based treatment. And here's the observation. You can find plenty of skeptics willing to tell you that homeopathy is just a placebo, and you can find plenty of homeopathists willing to tell you otherwise. A debate that is much less popular, however, is: what are the ethics of providing people with placebo-based treatment?

Ugly isn't it. I've discussed in the past how alternative medicine has sometimes been used to fob off the underclass because the money or expertise simply wasn't there to provide conventional medicine to the masses. The trouble is, as the money and expertise isn't there, what else do you do?

From what I can gather, the NHS ideal is that medicines should stand on their evidence base (though how many common treatments have evidence is surprisingly low), and that patients should be allowed to make informed choices about the treatments they receive. We measure treatments against placebos, so no placebo-based treatment has evidence, and part of the mechanic of placebos is deception, which goes against the idea of informed choice. The path seems clear, then, were it not for the fact that the placebo effect is real; certainly real enough to require placebo control arms in the first place. If no other treatment is available, is it ethical to deprive someone of genuine placebo-based relief in order to maintain the honesty and sanctity of the doctor-patient relationship. Are some homeopathists standing their ground in the face of evidence not because they believe in the magic water, but because they are defending their placebo; keeping the lie in place so that the medicine remains effective.

I've often wondered if there would be ethical and practical grounding in signing off a placebo-waiver whenever you register with a surgery. This would form an explicit agreement between you and your GP that they are able, where no other treatment is viable, to prescribe a placebo. What I like about this idea is that it crosses a line that I think exists in quite a few people's heads. When they discuss how placebos should be available, they tend to couch it in terms relating to other people, and rarely in terms relating to themselves. Plenty of people say "give them placebos", I've heard very few say "give me placebos".

Beyond these arguments are "bigger picture" positions. Getting sugar pills from your GP to help you over the doldrums sadly uses the same lie that leads the genuinely deluded to go off to Africa to try and cure HIV AIDS. If your sugar pill is based on pseudoscience, to legitimise its use in one area legitimises its use everywhere. Ironically a way round this would be to manufacture your placebos as if they were pharmaceutical products, specific active ingredients operating on obscure aspects of human physiology. That way you couldn't possibly be propping upthe beliefs of dangerous fanatics. Except that they're also trying to cure HIV AIDS with vitamin C... 

I'm proudly undecided about the ethics of placebo treatment. I can see valid, if difficult to weigh, points on either side of the discussion, and know that personally I would rather the truth, however bitter a pill to swallow, even when it denies me relief. What pains me more, though, is that few people seem willing enough even to have the debate in the first place, despite it being the only alternative medicine discussion actually worth having.

4 comments:

  1. One point I would make is that placebo treatments are freely available over the counter. Placebo treatments are also available privately and some medical insurance schemes are happy to fund them as well.

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  2. Even though you brought up some interesting ideas,I think you are getting off the wrong track by consistently referring to homeopathy as 'placebo' It is much more than that - despite science's inablity, thus far anyway, to be able to measure energy.
    And, on the topic of placebo, how much of the so-called success of conventional pharmaceuticals could really be dependent on a 'placebo' effect? I think as much as in homeopathy....
    Some things are difficult to prove, like attraction, love, etc - does that make it null and void?
    Instead of ridiculing homeopathy, maybe one should try it...I did, and was amazed.
    Melissa Burch

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  3. Hi Melissa,

    I'm not sure what you mean by "science's... inability to measure energy". As for homeopathy itself, if it can't be shown to be more effective than placebo in a randomised controlled clinical trial then it cannot be show to be effective *anywhere*. The whole need for running trials in the first place is that personal experience is not enough to determine whether a treatment is effective. I'd recommend you read either Bad Science by Ben Goldacre or Trick or Treatment by Ernst & Singh, as they explain this further and better than I ever could.

    I will say you have demonstrated part of the problem, though. Rather than looking at the ethics of placebo-treatment, you are more interested in defending homeopathy.

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  4. Melissa

    Obviously science can measure some forms of energy - can you explain what energy you're talking about?

    Thanks.

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