Evidence based medicine: what is the evidence?


Medicine today prides itself on being evidence based, meaning that our practice is not random or whimsical, but scientific, based on treatments that have been tried and tested in clinical trials. What is the evidence for this form of evidence and is there another form of evidence that we are ignoring?

In my own practice, I practise evidence based medicine. I follow guidelines, read peer-reviewed journals, attend conferences, interact with my colleagues and do my best to make sense of it all and apply it to the best of my ability to the patient before me. But increasingly, I have become aware that the evidence we have come to rely on is not as reliable as we would like to believe it is. (1)

For example, an article was recently published in a prestigious journal (2) stating that there was no benefit in using an omega-3 fatty acid supplement over placebo capsules in the treatment of dry eye. But on reading the methods I found that the placebo used was olive oil, which is well known to be rich in omega-3s! This demonstrates at least two things: that doctors in general know little about nutrition; and that you can no longer read the abstract of an article and assume it to be true.

The history of evidence based medicine

Evidence based medicine grew out of an understanding that many medical treatments were historical and anecdotal in nature, had no scientifically proven benefit, and in some instances were actually doing harm.

There was an earnest desire to bring some science to the situation, to study our treatments, work out which ones worked and which did not, and to share this information with medical practitioners, so they could better treat their patients.

The term ‘evidence based medicine’ is attributed to Sackett et al in 1996 (3) who said:

“Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.” (3)


“Good doctors use both individual clinical expertise and the best available external evidence, and neither alone is enough. Without clinical expertise, practice risks becoming tyrannised by evidence, for even excellent external evidence may be inapplicable to or inappropriate for an individual patient. Without current best evidence, practice risks becoming rapidly out of date, to the detriment of patients.”(3)

This heralded a paradigm shift in the way we practise modern medicine.

The original impulse was laudable, arising in response to a genuine need for transparency and accountability, but it neglected one important fact:

There is no such thing as objective science.

The observer always influences the observation, through their own filters, their own ideals and beliefs, their own agenda, and often their own desired outcome.

The attempt to separate the observer from the observation, and to reduce the whole of which we are an integral part to something outside of us that we could observe, measure and control, began not last century, but with Aristotle, where reductionism in science has its roots, and this has had a profound effect on the evolution of Western civilisation. We left behind the understanding that “the part can never be well unless the whole is well” as Plato said in Charmides, and made our focus the part, at the great expense of the whole. We have reduced whole people to body parts and have specialised to the nth degree, focussing on becoming as good as we can at dealing with illness and disease in parts, but we are not taking care of the whole patient, the whole of ourselves, or the whole system we are operating in.

The double slit experiment

Even if we are not willing to look at our ancient history, quantum physics has known and shown us the truth that we cannot separate the observer and the observation for over a hundred years.

The double slit experiment (4) shows that when an observer observes an experiment, the results are different from when the event is not observed. Light behaves as a wave when it is left alone, and obligingly behaves like a particle when we attempt to observe it, even when we try and trick it by turning the observing camera off. The very act of observing it reduces light from the formless vibration it is – as waves – to the density of matter – as particles – and this principle applies not only on a quantum level, but to life as we live it in an everyday way.

Knowing this, we have a huge responsibility as observers to free ourselves of bias, investment, attachment, or any particular desired outcome, as much as is humanly possible, and to be aware of the fact that bias is inherent in the scientific process, no matter how much we would like to think otherwise.

Most current published research findings are false

We are increasingly being shown that, far from working with this fact and the humility it brings, much of modern research is flawed and subject to bias. John P.A. Ioannidis, in his landmark paper (5) stated:

“There is increasing concern that most current published research findings are false.”


“…for many current scientific fields, claimed research findings may often be simply accurate measures of the prevailing bias.”

When studies are repeated to determine their reliability, in only 38.0% can the findings be confirmed and in 40.2% the findings reversed the current clinical practice. (6)

If this is the case, why are we still so steadfast in our support of evidence based medicine?

Marcia Angell, editor of the New England Journal of Medicine, said in 2009:

“It is simply no longer possible to believe much of the clinical research that is published, or to rely on the judgment of trusted physicians or authoritative medical guidelines. I take no pleasure in this conclusion, which I reached slowly and reluctantly over my two decades as editor of The New England Journal of Medicine.” (7)

Richard Horton, at the time the editor of the Lancet, said:

“The case against science is straightforward: much of the scientific literature, perhaps half, may simply be untrue. Afflicted by studies with small sample sizes, tiny effects, invalid exploratory analyses, and flagrant conflicts of interest, together with an obsession for pursuing fashionable trends of dubious importance, science has taken a turn towards darkness.” (8)

What is the evidence for evidence based medicine?

It is evident from the state of medicine today, that this evidence based approach to medicine is not the whole truth, and is not supporting us to live healthy lives.

  • There are >2,000,000 papers published each year, but our patients only benefit from a tiny fraction of these studies (9)
  • We are not well, as individuals and as a society: over 95% of us are ill. According to a study published in the Lancet in 2015 (10), less than 1 in 20 people worldwide (4.3%) had no health problems in 2013, with a third of the world (2.3 billion people) experiencing more than five ailments.
  • We are sicker than we were last century. Worldwide, the number of people with several illnesses increased both with age and in absolute terms between 1990 and 2013. And the number of people with more than 10 disorders increased by 52% between 1990 and 2013. (10)
  • According to the WHO, the major causes of chronic diseases are known and 80% of all heart disease, stroke and diabetes could be prevented and are lifestyle related (11) and 40% of all cancer could be prevented.
  • Despite our intense focus on the genetic basis for diseases, and in particular, our focus on cancer, it has been shown that only 5% of cancers have a genetic basis (12) and the rest are related to our lifestyle, to the way we live.

So, if the evidence is showing us that evidence based science and medicine are not the whole truth, cannot be completely trusted, and they not able to keep us healthy and well, but that we are in fact getting sicker as a species, largely from lifestyle related diseases, what other evidence can we turn to?

The evidence of our bodies

This time-honoured method of gathering evidence has been termed anecdotal evidence, which comprises listening to what our body is saying and communicating it. This is a personal communication and cannot always be generalised to the whole, but this does not mean it is not valid evidence. Doctors rely on anecdotal evidence when taking a patient’s history, and the law relies on anecdotal evidence when prosecuting alleged criminals.

Our body is the magnificent biofeedback mechanism that we live in, that is always with us, always communicating to us, helping us to learn about life and how to live it.

Our bodies are the marker of the truth of our living way and are always communicating to us how to live:

  • How do I feel after I eat that food or drink that drink?
  • How did that conversation make me feel?
  • When I am with that person, how do I feel?
  • When I act in that way, how do I feel afterwards?

Why don’t we listen to our body?

Why do we override it?

Why do we do things we know are not good for us, over and over again?

The evidence is pointing to the fact that there is a character running the body, doing what it likes, in ways that are not always in our best interests … in fact, they usually are not!

And the more ‘intelligent’ we are, the more willing we seem to be to override the innate wisdom that lives inside us, the simplicity of knowing what to eat and drink, when to wake up and go to bed, how much to work, how to move, how to be in relationship with people …

What is it about this intelligence that thinks it knows better than the body?

And where has this intelligence taken us, as individuals and as a race of human beings?

Perhaps it is time we started to truly look, not only at the ‘scientific’ evidence, but at the living evidence of our own bodies as to how we are really doing in life, not just at our bank balance, our cars and houses, the letters after our names, and all the other stuff we accumulate along the way.

This is not about an either/or, of rejecting the evidence based science that truly serves, but about re-expanding our awareness back to include the whole of what constitutes evidence, our whole bodies, in conjunction with the tools we currently use.

For too long we have allowed the intellect to dominate the way, neglecting the evidence of what our bodies know to be true. The classic example of this is the case of red wine being good for the heart; we have accumulated buckets of evidence to justify our stance, and this evidence has recently been overturned in a meta-analysis (13) … but our bodies have always known the truth, that drinking alcohol is not good for us, in any amount, and as the consciousness around this is being cleared, more studies are coming out to support this truth, including that alcohol, in any amount, causes cancer (14).

We have to start somewhere … true change and innovation start with one person observing something, then deepening their understanding and awareness of it, and with that, they feel a responsibility to test that observation … and that is how clinical trials begin. So how can we dismiss the evidence that starts it all … the living evidence of our own bodies?

Perhaps it is time we started letting the intelligence of the body guide the way to a deeper and truer way to live. People who live in this way, which deeply honours the body, experience greater health, vitality and wellbeing. What if our way forward is a return to the true medicine that knows the evidence of our bodies is gold, for they are the instrument that reflects the truth of our choices, resulting in either illness and disease or health, harmony and vitality. 


  1. http://journals.sagepub.com/doi/pdf/10.23907/2016.055

Invited Review

  1. http://www.nejm.org/doi/full/10.1056/NEJMoa1709691

n−3 Fatty Acid Supplementation for the Treatment of Dry Eye Disease

  1. https://www.cebma.org/wp-content/uploads/Sackett-Evidence-Based-Medicine.pdf

Evidence based medicine: what it is and what it isn’t

  1. https://www.youtube.com/watch?v=A9tKncAdlHQ

Double Slit Experiment explained! by Jim Al-Khalili

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1182327/

Why Most Published Research Findings Are False

  1. https://www.ncbi.nlm.nih.gov/pubmed/23871230

A decade of reversal: an analysis of 146 contradicted medical practices.

  1. http://www.nybooks.com/articles/2009/01/15/drug-companies-doctorsa-story-of-corruption/

Drug Companies & Doctors: A Story of Corruption

  1. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(15)60696-1/fulltext

Offline: What is medicine’s 5 sigma?

  1. https://lifeinthefastlane.com/ccc/evidence-based-medicine/

Evidence Based Medicine

  1. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(15)60692-4/abstract?code=lancet-site

Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013

  1. http://www.who.int/chp/chronic_disease_report/part1/en/index11.html

WHO Overview – Preventing chronic diseases: a vital investment

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515569/

Cancer is a Preventable Disease that Requires Major Lifestyle Changes

  1. https://www.ncbi.nlm.nih.gov/pubmed/28499102

Alcohol Consumption and Mortality From Coronary Heart Disease: An Updated Meta-Analysis of Cohort Studies.

  1. https://wiki.cancer.org.au/policy/Position_statement_-_Alcohol_and_cancer

Cancer Council Australia – Position statement – Alcohol and cancer risk



  1. Great article Anne. It certainly puts the origin and role of evidence-based medicine in perspective and highlights the need for us to be aware of what our bodies are telling us – and to respond to this information!

  2. This is a fabulous article Anne, free of the reaction a lot of medical practitioners experience when they feel themselves forced to perform medicine in accordance with the evidence base. As you have stated, there is nothing wrong with EBM, as long as we are prepared to be open and honest about its imperfection, and as long as we give equal scope to practice on the basis of experience and our own observations. I suspect EBM will assume its correct proportion in our practice as more truth about it flaws, biases and corruption, slow and steadily emerge.

  3. Thank-you Anne for this wonderful informative blog. Everything has to be taken into account and it makes sense that the key factor is to listen to our bodies and what it is showing us when it comes to our health to take responsibility for the way we choose to run our body – that is for our lifestyle choices. That is surely the best evidence we can rely on.

  4. Thank you Anne. Its great to read a common sense article on Evidence Base Medicine. I have been to a number of courses this year and quite a number of specialist doctors, during their presentations talked about how there was no to little evidence on what they were sharing or presenting on. Given this they still provided care and support for the patient/s concerned, regardless of the lack of evidence. They were able to draw on their experience as senior clinicians, their experience in working with people, their experience in observation to decide on approaches to treatment. I have even seen a medical clinician prescribe a medication in a dose, not evidenced based, based on what the patient was saying about how they responded to this medication, showing complete and total respect to the what the person was saying about how their own body responded. This to me highlights that evidence is absolutely important, but there are many ways to gauge what evidence is and that it cannot be narrowed or placed on a rung of importance because of a method used to find a particular result.


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