Sunday, 19 September 2010
Pain Relief, Placebo and Profit
Glucosamine and chondroitin have no effect on osteoarthritis of the hip and knee. Researchers at Bern University in Switzerland ran a meta-analysis of ten trials on the two treatments and found that they perform no better than placebo - as reported in the BMJ.
The analysis confirmed what the BMJ reported nearly ten years ago. It concluded that: Our findings indicate that glucosamine, chondroitin, and their combination do not result in a relevant reduction of joint pain nor affect joint space narrowing compared with placebo. Some patients, however, are convinced that these preparations are beneficial, which might be because of the natural course of osteoarthritis, regression to the mean, or the placebo effect. We are confident that neither of the preparations is dangerous. Therefore, we see no harm in having patients continue these preparations as long as they perceive a benefit and cover the costs of treatment themselves. Coverage of costs by health authorities or health insurers for these preparations and novel prescriptions to patients who have not received other treatments should be discouraged.
The global glucosamine market was worth £1.3bn in 2008.
The findings have been reported by the Telegraph, Independent, Mail and BBC among others. It is unlikely that now the truth is out, sales will fall. Evidence that something doesn't work has made no impact on other products. Reports like the ones here and here that antioxidants don't work have not stopped countless products being sold that proudly proclaim they contain them. Marketing rarely lets the facts get in the way of making money.
Boots sells Ladycare Magnets that allegedly treat the symptoms of menopause through magnotherapy even though there is absolutely no evidence they work and plenty that they can't possibly.
A Boots spokesman notoriously said that Boots doesn’t sell homeopathic remedies because they work, they sell them because people like to buy them: "I have no evidence to suggest that [homeopathic remedies] are efficacious. It's about consumer choice and a large number of our customers think they work."
There are plenty of other products that don't or can't work - the beauty industry is full of them, for example.
There are two issues here. One is freedom of choice. The research recommends that the NHS does not spend money on glucosamine and chondroitin but if people want to buy a product, that's up to them. However, if they think they are buying one thing (a medically-proven treatment) and they're getting another (a placebo) then arguably they are being mis-sold. It could also be argued that it's up to all of us to inform ourselves about what we're buying. But checking out the fat content on the back of a pizza in the supermarket is not the same as reading small print on apparently medical products, checking out academic research or even, in some cases, understanding media reports of research. Most people don't have the time, the will or the ability to do it. They're much more likely to buy on the recommendation of someone they know and trust (it worked for me). What's more, there may well not be any small print to check out.
The second issue is the ethics of placebo, which has been much discussed. Does it matter if feeling better is not the same as being better? Pain is one of the conditions that placebos work on particularly well and osteoarthritis can be very painful. Medical treatments for long-term pain can have side-effects while glucosamine and chondroitin apparently don't. How many of us actually know how any of the prescription medicines we get from the doctor work? If I had a long-term condition that medicine couldn't cure but which could be managed, then I think I'd rather get my placebo from a doctor who has fully diagnosed my condition, assessed all available treatments and will continue to monitor my progress than be left to the mercies of advertising and anecdote.
This leaves patients in a dilemma. If they do research their condition and possible treatments and find out that the only treatments that may help are placebos, will they still work? In order to save the NHS money, would it be ethical for doctors to recommend patients buy specific over-the-counter treatments rather than giving prescriptions? This way, patients get medical care but the NHS doesn't foot the bill for placebos. But then there is the question of what happens to people on low incomes. One potentially discriminatory effect of the Bern researchers' proposal is that the benefits of placebo will be available only to people who can afford them. This is the status quo as GPs are currently being advised not to prescribe glucosamine, but if over-the-counter is the only way people can buy placebos, is this equitable?
The placebo debate is not going to be resolved any time soon but the fact that yet more products have been proven to have no real effect means that it's not a debate that can be ignored. In the meantime, the manufacturers continue to make billions. One aspect that can be dealt with more simply is regulating labelling; claims like 'Promotes Natural Cartilage Regeneration' should be removed as this is demonstrably not true unless they are using a meaning of 'promotes' unknown to any other English speaker.