One of my teachers in medical school kept saying: ‘A treatment that has no side-effects is already a good one.’ These seemed to be wise words worth remembering. But today I think he may have been not entirely correct: there is no therapy that does not have potential to cause adverse effects. What really counts, in life as in medicine, is a reasonable balance between risk and benefit.
Chiropractic treatment is an excellent example of the importance of this balance. Chiropractors rely heavily on manipulating their patients’ spines, and the benefits are not at all clear. Practitioners usually insist that their manipulations are effective for a bafflingly wide range of conditions. On the internet, for instance, it is hard to find an illness that chiropractors do not claim to cure. However, the published evidence generally reveals these claims to be little more than wishful thinking. Therefore, even relatively minor side-effects might tilt the risk/benefit balance into the negative.
There is now a lot of evidence showing that more than half of all patients suffer mild to moderate adverse effects after seeing a chiropractor. These are mostly local and referred pains that usually last for two to three days. Chiropractors often claim that these are necessary steps on the road to getting better. On a good day, we might even believe them.
But unfortunately there is more, much more. Several hundred cases have been documented in which patients were seriously and often permanently damaged after chiropractic manipulations. The latest to hit the headlines was that of a 32-year-old woman from Jakarta who died after being treated by an American chiropractor. What usually happens in these tragic instances is that, upon manipulation of the upper spine, an artery supplying the brain is over-stretched and simply breaks up, leading to a stroke which can prove fatal.
Chiropractors do not like to hear any of this, and either claim that these are extremely rare events, or deny any connection with their manipulations. Regrettably, the hard evidence is not as solid as one would wish. In conventional medicine we have effective systems to monitor adverse effects of all interventions — not so in alternative medicine. Therefore, the true frequency of such tragedies is anyone’s guess. About 30 deaths after chiropractic have been documented in medical literature, but they are probably just the tip of a much bigger iceberg. We have shown, for instance, that in the UK the under-reporting of such instances is very close to 100 per cent.
All clinicians, alternative or conventional, must obtain informed consent from patients before starting a therapy. This ethical imperative means chiropractors must tell their patients firstly about the very limited evidence that spinal manipulations are effective; secondly, about the possibility of causing serious harm; and thirdly about other treatments which might be better. But who would give their consent, knowing all this? The way many chiropractors solve this dilemma is simple: they ignore the ethical imperative by treating patients without informed consent. There is evidence to suggest that ‘only 23 per cent [of UK chiropractors] report always discussing serious risk’.
How can this be? Chiropractic is a respected and well-established profession, you might think. True, in the UK, chiropractors have been regulated for many years by statute and have their own Royal College and General Chiropractic Council. But in July 2014, the Professional Standards Authority conducted an audit of the GCC and concluded that although the GCC’s operation of its processes had not created risks to public safety, ‘the extent of the deficiencies we found… raises concern about the extent to which the public can have confidence in the GCC’s operation…’
I have often said that the even the best regulation of nonsense must result in nonsense. The PSA’s verdict seems to support my view. As long as serious doubts about the value and integrity of chiropractic exist, we should remember an important foundation of health care: the precautionary principle. It compels us to use, whenever possible, only those therapies which demonstrably generate more good than harm. A critical analysis of the evidence shows that chiropractic does not belong to this category.
Edzard Ernst is Emeritus Professor of Complementary Medicine at the University of Exeter.