Sunday, 7 March 2010

Placebo - a discussion

The spam filters at libdemvoice as obviously quite strict, as they seem to gobble up my comments on an interesting discussion happening there regarding the placebo effect. So here are my comments:

shame I've some late to this - at the risk of making this into a Sunday debate, here's me sticking my oar in.

I am in broad agreement with the 'lying is wrong' position many of you have taken - as was mentioned previously, if my GP can tell me that treatment X will make me feel better (X being homeopathy) when there's no evidence that it will, what's to stop them from saying that Y will make me feel better too (when Y is, as Jock via Ben Goldacre alludes to, is a drug that is being sold as efficacious in the absence of evidence)? Breaking the doctor-patient trust bond is a very dangerous road to go down in my opinion.

Another argument to go against the routine prescription of placebo is the one James Cole deployed - that in many cases people do not respond. If we are to decide on which treatments are acceptable for prescription by the NHS on grounds of efficacy, routine placebo prescription would fall at the first hurdle.

To deal with Jock's assertion, from Goldacre's work, that many currently-available drugs do not have evidence for efficacy, I would say this: we must be sure to hold all treatments, whether pharmaceutical or so-called alternative, to the same rigorous standards, and one-by-one eliminate those that do not have a strong evidence basis. If that means investigating the way in which some drugs are approved, and it means altering current clinical practice, then so be it - evidence-based medicine must not be afraid to ask difficult questions of anyone, homeopaths or Big Pharma included.

Nonetheless, I do think that using this as a defence of NHS homeopathy (the 'but-he-started-it' defence) is something of a straw man - yes we need to ensure that only those drugs that have a basis in evidence are approved for use, but that shouldn't distract from the fact that public money is being wasted on ineffective nonsense.

Lastly, I want to acknowledge this comment by Alec Dauncey:
scientific medicine should immediately take account of the apparent benefits of longer more comprehensive consultations with practitioners.
There is no doubt that the placebo effect, where it is found to be effective, is one of the most interesting aspects of medical psychology, and that mainstream medicine has much to learn from it. In the blog post that James Cole linked to, and in the Neuroskeptic post linked to therein, there is a discussion of medicalisation - were we prescribe a pill/intervention knowing that the condition is self-limiting and/or not overly harmful. In learning from placebo-based interventions, I would imagine medicine could apply some of the techniques of long consultation, along with the power of giving the patient the impression that what they're taking/doing/eating gives them control over their symptoms. These are aspects of placebo that medicine could integrate into its management of people with chronic, phasic, self-limiting conditions - I would hope this could be done without the need to knowingly dispense an inactive pill, which I still feel is deeply unethical.

Hmm, food for thought...

I'll try and expand on this during the week if I can, for now it's enough to say that whilst it's tempting to want to harness the seemingly powerful effect of placebo, if medicine is to remain an honest pursuit of evidence-based treatments then there seems little place for the routine prescription of empty promises.

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