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Just because a patient gets better, doesn't mean their treatment worked

Doctors and complementary and alternative medicine practitioners can be similarly delusional about the effectiveness of their treatments, Professor Edzard Ernst argues.

Doctors and complementary and alternative medicine practitioners can be similarly delusional about the effectiveness of their treatments, Professor Edzard Ernst argues.

One of my first encounters with a "real" patient – at the time I was a medical student – was with a middle-aged woman who I had wired up for an ECG. After I disconnected her, she thanked me and said "that was brilliant, my angina is completely gone". At first, I was amused but then her remark made me think. How could a diagnostic procedure be experienced as therapeutically helpful?

After graduating from medical school, I pursued a career as a hospital doctor and was often impressed with the success of my treatments. The type of snug self-confidence began to take hold of me which I today sometimes recognise on the faces of clinicians when discussing the nature of clinical evidence with them. On several occasions, however, I used therapies which, according to research, later turned out to be useless or even harmful. How could harmful or ineffective treatments be so evidently helpful?


41225412I guess all doctors have similar experiences, but not all of us draw the same conclusions. Most clinicians, particularly those working in CAM, choose to be misled by their own experience. What we see with our own eyes must be true – as the sun visibly rises in the east and sets in the west everyday, it is obvious that it orbits around the earth. Sometimes, the obvious is not the truth!

After a few years as a clinician, I became a scientist which taught me, amongst other things, critical thinking. Remarkably this was something I had not learnt in medical school. A key issue which fascinated me for many years was this: what exactly causes patients to get better or (to be exact) to say they have improved? I still think that this is one of the most challenging questions for clinical medicine. Trying to find the answer might change your practice considerably – it has certainly changed mine!

Patients improve as a result of the treatment we prescribe, we like to think. For a while, I could convince myself of this notion. Medics of all times did the same; they probably had to believe it in order to carry on. But sadly it does not withstand critical evaluation. Patients may (and often do) get better, even if we prescribe entirely useless (or even harmful) treatments.

My answer to the question "why?" turned out to be much more complex than I, as a young doctor, had thought. Not one but a whole range of factors can be involved, and the relative importance of each single factor may differ from case to case. For instance, the natural history of the disease and the regression towards the mean may have it that our patient improves whatever we do. Then there are the placebo-effect and treatments that patients use without telling us. And some patients say they are better only to please us. The list could go on….

If all this is true, and I am sure it is, the implications are considerable: in clinical practice, we can never be sure what precisely the cause of any clinical outcome is. To pretend otherwise creates false certainty which can backfire. This means that clinicians' experience is woefully unreliable. The only evidence, when it comes to the effectiveness of medical interventions, is that from rigorous, reliable, clinical trials. They control for all the non-specific factors and can tell us exactly what the specific effects of our treatment are.

Clinicians don't like to hear this at all. Often they get irritated and argue "it doesn't matter how we help our patients; all that counts is that they get better". In CAM, this argument is frequently used as a ‘carte blanche' to use all sorts of ineffective or even harmful treatments "because patients like it". And this, I think, is the best proof for its absurdity.

Professor Edzard Ernst Pull quote Recent posts

Homeopathy for cancer is nothing more than placebo 23 April 09
Do complementary and alternative therapies do more harm than good?
20 April 09
Don't let your practice become an evidence-free zone
15 April 09
Natural doesn't mean safe. And CAM is neither
06 April 09

So-called 'integrated medicine' is disturbing nonsense 30 March 09

Why 'belief' in complementary medicine is misguided
23 March 09

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