Trick or Treatment—The Undeniable Facts about Alternative Medicine (Electronic book text)

But, if we temporarily suspend disbelief and leave the underlying philosophy to one side, the key question is straightforward: does chiropractic therapy help patients? Fortunately, this is a question that has been addressed thanks to evidence-based medicine and the use of clinical trials.

So far, evidence-based medicine has generated a pessimistic view of alternative medicine. Acupuncturists and homeopaths have spent centuries developing treatments to help patients, and yet scientists have examined the evidence, mainly from clinical trials, and concluded that these therapies are over-hyped. Acupuncture appears to be nothing more than a placebo for everything except some types of pain and nausea, and the jury is out even for these conditions. Worse still, homeopathic remedies have failed to be more effective than placebos in the treatment of every known condition.

Some readers may start to suspect that evidence-based medicine is somehow biased against alternative medicine. Perhaps acupuncture and homeopathy are actually valid therapies, and instead maybe it is in fact the clinical trial that is at fault? Perhaps the clinical trial is part of an establishment conspiracy cooked up by doctors and scientists to protect themselves from the interference of meddling outsiders? Just in case you are harbouring any such suspicions, let us take another look at the clinical trial and evidence-based medicine in general before examining the evidence for and against chiropractic therapy.

Evidence-based tea

The core principle of the trial is simple and can be traced back as far as the thirteenth century, when the Holy Roman Emperor Frederick II conducted an experiment to find out the effects of exercise on digestion. Two knights consumed identical meals, and then one went hunting while the other rested in bed. Several hours later, both knights were killed and the contents of their alimentary canals were examined. This revealed that digestion had progressed further in the sleeping knight. It was crucial to have two knights undergoing different levels of exercise, active and at rest, as it allowed the degree of digestion in one to be compared against the other. The key point of a trial is to compare the consequences of two or more situations.

The modern clinical trial, as developed by James Lind to test cures for scurvy in the eighteenth century, is less brutal than Frederick II’s trial, but the central idea is the same. If, for example, a novel treatment is to be tested, then it needs to be compared against something else, known as the control. That is why the novel treatment is given to one group of patients and the control is given to another group. The control can be an established treatment, or a placebo or anything at all. Afterwards the patients in both groups are assessed, so that the effect of the novel treatment can be compared against the control.

Sir Ron Fisher, a British pioneer of the use of trials in the twentieth century, used to recount a story that amply demonstrated the simplicity and power of the trial. While at Cambridge, he became embroiled in an argument over how to make the ideal cup of tea. A woman insisted that it tasted worse if milk was added to the tea as compared to when tea was added to the milk, but the scientists around the table argued that it made no difference at all. Fisher immediately proposed a trial — in this case the comparison was the taste of milk added to tea versus the taste of tea added to milk.

Several cups were made with milk added to the tea, and several with tea added to the milk, and the woman was challenged to identify which was which. Although the cups of tea were prepared in secret and were identical in all other ways, the woman could indeed correctly recognize in each case whether the tea had been added to the milk or vice versa. The trial had shown that there was a difference, that the woman was right and that the scientists were wrong. In fact, there is a good scientific reason why the two forms of tea should taste different. Milk added to tea leads to a less satisfying cup, because the milk becomes superheated and this causes proteins in the milk to deteriorate — these proteins then taste slightly sour.

Fisher used this simple example as the basis for an entire book on scientific testing, The Design of Experiments, which went into great detail about the subtleties of trials.