Evidence-base medicine: the case against

No sooner had I finished a post extolling the merits of evidence-based medicine (EBM) than I found my certainty that it was unquestionable being decisively questioned by an outstanding presentation at the same conference. 

That was a challenging but refreshing experience.

Trisha Greenhalgh
an authority on evidence-based medicine and a challenging patient

Trisha Greenhalgh is Professor of Primary Care Health Sciences at Oxford University. That makes her a leading authority in this field. In fact, she was awarded the Order of the British Empire in 2001 for her work on evidence-based medicine. So when she speaks out about its limitations, she commands attention – certainly mine.

Not that she advocates turning our backs on evidence. She simply calls for us to make more use what she calls “patient evidence”. The “old-fashioned clinical method” asks a key question:

What do I know about this patient: her history, the examination, test results, how she reacted the last time she took this drug, her beliefs, her family circumstances, etc. And given all that, what evidence do I need?

Without knowledge of the patient, the clinician may well pick the wrong evidence. Greenhalgh feels that clinicians don’t apply “old fashioned clinical methods” anything like often enough, as became clear after her own hospitalisation following a serious bicycle accident. Here’s what happened as she subjectively perceived it:

I was riding my racing bike along the towpath. I was going about 20 miles an hour.

Something caught in my front wheel. The bike somersaulted into the air. I came down heavily on the concrete, landing on my arms and the back of my head.

I was very dazed. Both my arms were deformed and useless. My fingers were numb. My helmet was split.

This was converted by the hospital into the following “objective” narrative:

55 yr old female fell off her bike

The hospital chose to apply a guideline for an older woman at danger of a fall. 

The fractures to both her arms led to seven operations over four months. But after six months she had wasting of both hands, together with heaviness, clumsiness and hyperreflexia (excessively pronounced reflex reactions) in the legs.

The guideline didn’t provide for any kind of diagnostic testing to the spine but eventually an MRI scan was carried out, revealing a displacement of two discs in her cervical spine (the neck).

In passing, let me say that an American in the audience pointed out that in the States the spinal examination would certainly have been carried out (“and billed”, cried a voice in a distinctly English accent). But, as Greenhalgh made clear, it should have been carried out in Britain too. 

NICE, the National Institute for Health and Care Excellence, provides a guideline which includes an algorithm for Selection of adults for imaging of the cervical spine. It calls on staff dealing with “adults presenting to the emergency department who have sustained a head injury” to check on the presence of any of a series of risk factors, including “dangerous mechanism of injury (fall from over 1 metre or 5 stairs)” or “ejection from a motor vehicle”.

A bike is not a motor vehicle, but surely the key condition is the ejection. And since the bike rose high in the air, she fell from over a metre. Her point is that it takes judgement to decide which guideline to apply. It isn’t a simple mechanical process.

She decided to have surgery. But it seems that some “self-proclaimed experts in evidence-based medicine” told her:

You didn’t need that operation. Randomised clinical trials have shown that in cervical disc lesions, surgical groups didn’t do any better than conservatively managed groups.

She stressed that:

They said this without taking a full history, without asking what the examination or MRI findings were, and without acknowledging the inclusion/exclusion criteria for the trials.

Yep. Got to agree with Greenhalgh on that one

As an authority in the field, she dug out the trial report. It specifically excluded patients with obvious muscle wasting, from which she was suffering, or who had undergone a whiplash-type of injury.

Things got worse when she needed to treat the acute pain she suffered after the operation. The specific question was whether she should use an opioid-based analgesic or a non-steroidal anti-inflammatory drug (NSAID). The evidence-based view was:

Patient advised not to take NSAIDs for one month following surgery: “some evidence of delayed healing of bone repairs, and risk of bleeding is higher in the post-op period”

The evidence that NSAIDs slowed healing was from a 2011 study.

It was based on work on just 12 subjects.

All of whom were rats. And I don’t mean politicians. Rodents with long tails.

Greenhalgh, formerly an elite athlete, had plenty of experience of taking NSAIDs, even after bone fractures, with no evidence of delayed healing. As for opioids, she had taken them with some severe adverse reactions in the past, including itching and vomiting.

As she pointed out, the conclusion had to be:

In this patient, given the history, clinical picture and equivocal nature of the evidence, the benefit-harm balance is in favour of NSAIDs...

Her presentation reached two conclusions. One, she rightly maintained, was uncontroversial. Clinicians should ask themselves:

Is the management of this patient in these circumstances an appropriate (‘real’) or inappropriate (‘rubbish’) application of the principles of EBM?

The second conclusion is far more controversial and more interesting:

If we practice patient-focused, individualization of the evidence (also known as real EBM) we will often find that more research is not needed.

Perhaps the uncertainty in science is inherent.

Perhaps we need to return to old-fashioned clinical method and use EBM less comprehensively…

A challenging conclusion indeed. But if it stops clinicians allowing their view of the patient to be blinded by a mountain of not necessarily relevant evidence, that has to be good news for us all. Any of us might some day be patients.

Not that this means the need for evidence is less strong. Only that the application of evidence has to be guided by the real condition of the patient. Surely all clinicians would make that condition the starting point for medicine?

Wouldn’t they?

Healthcare: doing the right thing and finding the right words to say it

Every now and then a conference – and I’m at one now – is enlivened by masterful presentation, brimming with insights on vital matters, the whole sharpened and enhanced by intelligent use of humour.

Such was the talk given by Walter Ricciardi, President of the Italian National Institute of Health. It was entitled From evidence to action in health policy making: a mission impossible? His subject was how senior clinicians concerned with the strategic direction of health, and convinced of the value of practising evidence-based medicine (the theme of the conference) could work with politicians in government to take the necessary decisions.

Walter Ricciardi
Witty, insightful and spot on about the need to get it right – and say it right

I’m keen on evidence-based medicine. That may sound like a trivial statement: who wouldn’t be? Well, you might be surprised how often medical decisions are taken on the basis of a clinician’s gut feel, or confidence that years of experience are enough, rather than evidence. Worse still, they’re often taken on the basis of politics: for instance, the UK government has made funds available to allow GP practices to stay open later, without putting in place any kind of process to check whether the move leads to any of the desired effects – most notably reducing attendances at Emergency Departments of hospitals.

The reason why Ricciardi feels this kind of discussion is vital now is the well-known observation that demand for healthcare seems to keep climbing uninterruptedly, as the population of the advanced economies ages and the technology available for care increases in sophistication (and cost). As he suggested, there has to be a limit to the amount society can sensibly be asked to invest in healthcare.

That reminded me of a presentation I attended some years ago, when one of the speakers pointed out that, on present trends, the USA would be spending 100% of its GDP on healthcare by the end of this century. That’s clearly impossible – something has to go into schools and roads and things, to say nothing (this is the USA we’re talking about, after all) about defence. So what is the maximum US citizens will accept? 50%? Surely that’s too high. 30%? It’s hard to imagine. 20%? If so, things are urgent indeed: they’re already spending 18%.

That’s without even providing full healthcare coverage for the whole population.

Limiting healthcare expenditure, wherever the limit lies, means that at some stage we’re going to have to start denying care. That’s where evidence-based medicine comes in. There are a great many treatments that could be denied without doing patients any harm – indeed, where the denial would do them good.

At one end of the scale, prescribing antibiotics for viral conditions harms us all and does no good to the patient.

At the other end, intense and highly expensive interventions for a patient with a fatal condition can wreck the end of a life and incur huge waste.

We have to start finding a way to avoid this kind of wasteful, if not downright harmful, way of practising medicine.

That’s where Ricciardi turned up the humour a notch or two. He suggested that the people who understand the issues have a vocabulary of 140,000 words; the general public, and he included politicians in that category, a mere 7000.

I don’t know where those numbers came from. Frankly I find them highly questionable. In fact, I’m inclined to ask, where’s the evidence? However, the underlying point is worth making: specialists in medical information need to find a way of communicating the case for some of these notions more effectively to the population. They need to persuade politicians of the need for action, and help the politicians find the words to express their decision in a way voters will accept.

At this point he made a point I found particularly amusing, though he may have meant it seriously. He referred to Jean-Claude Juncker, President of the European Commission, as intelligent and honest. It was wonderful to see how the English in the room all started in their seats and shuddered: Juncker is viewed as a figure of derision in England. He’s disliked in a great many countries, but it was striking how much stronger the English reaction was.

He went on to quote Juncker as saying, “we know what to do. We just don’t know how to get elected afterwards.”

Jean-Claude Juncker: a smart and honest politician?
Not according to the English, but are they right?

Now, that really is both honest and true. The things that need doing are tough to make popular. A politician that does them may indeed find it hard to win office again.

There’s an excellent example in Ricciardi’s own country, Italy: the Italian government has taken an extraordinarily courageous decision, to make childhood vaccinations compulsory. The anti-vax movement has reached dangerously high levels, with herd immunity being lost and long-vanished diseases like measles and mumps making an appearance again. The government took the action necessary, based on the mass of evidence available: the potential harms of the vaccinations are less serious and less common than those of the diseases they eradicate.

But will they have persuaded the voters that the decision was right? Popular anger in response to the measure was intense and widespread. We’ll see in next year’s elections how well the government has done in taking popular opinion with it.

It’s important to practise evidence-based medicine. But it’s just as important to find the words to explain what you’re doing. The former is what we have to do but, without the latter, the politicians who do it will be unable to stop their achievements being unravelled by their successors.