Over on Code for Life, Grant's recently put up some posts concerning homeopathy (here & here, for example). He's also suggested that homeopathic (& other) remedies should carry disclaimers to do with their active ingredients (or lack thereof) and what they can & can't do.
Anyway, one of the common responses to articles critical of homeopathy & other 'complementary & alternative medicines'** is that, even if they 'work' only via the placebo effect, at least they do no harm. I would argue that if the placebo effect masks an ongoing problem, then it is doing harm. And the same is true if patients are led to stop taking necessary medication. But - & I think more seriously - here's an example where following a homeopathic prescription may do considerable damage: homeopathic vaccinations.
The article I've linked to (posted by Peter Bowditch of ratbags.com, for purposes of serious critiquing) makes the following claim:
Homeopathic immunisation is effective against poliomyelitis, chickenpox, meningococcal disease, hepatitis (all types),Japanese encephalitis, Hib, influenza, measles, pneumococcal disease, cholera, smallpox, typhoid, typhus, whoopingcough, rubella, mumps, diphtheria, malaria, tetanus, yellow fever, dysentery, and many other epidemic diseases.
Well, they're pretty safe in making this claim for smallpox as that's been eradicated in the wild, but the rest are still with us in various parts of the world. These are pretty extraordinary claims for products that, by their very nature, usually contain no molecules whatsoever of their supposed active ingredients. Most of the diseases on that list can be fatal if left untreated, & can leave survivors with ongoing physical problems. So you'd expect to see some decent evidence that homeopathic 'vaccines' actually perform as claimed - good, solid evidence-based data on patient outcomes. Not vague statements that lack names, dates & other data, which is all the article provides. Yet hard evidence appears to be lacking.
Take influenza, for example. Here's an evidence review from our Ministry of Health - a meta-analysis of a number of studies examining claims for a homeopathic 'remedy' called oscillococcinum (made from the liver of a dead duck, by the way, although it's so highly diluted that you would be hard-pressed to find any evidence at all of duck in your liquid or pills). Oscillococcinum is prescribed by many homeopaths as both a prophylactic & treatment for flu. The Ministry's evidence summary examined data from a systematic review & a total of 7 clinical trials (representing 3459 patients). Three of the trials (2265 patients) found that the oscillococcinum preparation did not prevent the flu. The other 4 trials looked at its efficacy in treating flu - oscillococcinum shortened the length of the illness by about 6 hours. In other words, this particular homeopathic remedy didn't do what was claimed for it; it acted as neither vaccine nor treatment. (There did appear to be some reduction in severity of flu symptoms, but as such data tend to be self-reported it's hard to be sure how much represented actual effect of the preparation & how much reflected patient expectations that they'd get better.)
But that's just the flu - what about the other claims made in that article? Since they're extremely vague, & cite no evidence whatsoever in their support, it's rather difficult to judge. But a scirus search for published data on the claimed efficacy of homeopathic treatment during a a supposed polio 'epidemic' in Buenos Aires turned up nothing. And frankly, if the stuff was that good I'd expect to see hard evidence of that fact. Given the potential severity of polio, I'm sure doctors around the globe would love to have an addition to the treatments available to them. But then, it seems that most individuals affected by polio don't progress to the severe paralytic form of the disease - so many of those Buenos Aires patients claimed as success stories for the homeopathic 'vaccine' may in fact have had the less severe infection, easily confused with the flu. With no actual data in the article, how can we tell?
So it's hard to see how the claims made in the article for homeopathy's ability to prevent serious, potentially lethal, infectious diseases can be supported. What's more, I wonder how those claims can sit with any code of conduct for homeopaths. After all, the Society of Homeopaths in the UK has a code of ehtics which clearly states that no advertising may be used which expressly or implicitly claims to cure named diseases. And another homeopathy site expressly states that TCAM practitioners are prohibited from... treating infectious, communicable diseases (which is pretty much everything on that list I cited). Where does the responsibility lie, if someone follows this advice, takes (for example) a malaria 'vaccine', contracts the falciparum form of the disease, and dies?
PS CAM isn't really the right term. If a treatment works, can be shown to work in a reliable manner, produces positive outcomes that can be confirmed by other workers in the field - then it's medicine. If it doesn't - whatever it is, medicine it's not.
And Ben Goldacre has an excellent article on the subject here.