What they mean by evidence based medicine.

I have mentioned before that the MS therapy centre I attend for hyperbaric oxygen is promoting a commercial 7 step treatment approach called "Overcoming MS". There is also an NHS approach called "Living Well with MS" which I have no quarrel with - the usual, eat well, exercise as much as you can, reduce stress - but there is a vast difference between living as well as possible and overcoming a disease like MS.

Today, I decided to read the leaflet giving the scientific references for the program. It had the usual problem of confusing correlation with causation but what was eye opening for me was the statement about evidence based medicine. I had to leave the leaflet behind so I don't remember who says it but it went something like this.

"Many scientists believe that we have to wait for properly run large scale trials before they can say anything definitive about treatments [such as the plant based diet they recommend or the large doses of vit D] but evidence based medicine means taking evidence from wherever it exists so individual patient experience is just as important."

So that explains a lot. When the likes of MS or the LP promoters use anecdote they feel that is valid evidence.

 

But whenever it suits the person talking, personal anecdote is dismissed as irrelevant and is not counted as evidence. For example, for years people with side effects from statins were told that anecdotes were not evidence or were not data. But I think the message has got through to most people now that statins have quite a high side-effect load on patients.

 

It's basically everything the scientific method was created to avoid. There is absolutely no issue with taking evidenced-based... evidence and using it as a starting point for more rigorous research. It's actually a great strategy as it generates more hypotheses.

But the current approach to EBM is built entirely to maximize bias and allow the promotion of quackery like BPS/FND, which cannot stand the scrutiny of a formal scientific process. I'm pretty certain that if it weren't for psychosomatics being so strongly believed EBM would not exist in its current form, it's pretty much the only reason it's happening in the first place. It's regress, plain and simple, a good idea in principle with a disastrous implementation precisely because it abuses the weaknesses inherent to this approach.

 

This is not what Evidence Based Medicine was intended to mean when it was proposed. It seems to be the usual post-truth modern version - politically correct, free of any discrimination, such as old wives' tale-ism (unfair discrimination against old wives' tales) our Facebook group says-ism (unfair discrimination against gossip of Facebook) and so on.

 

For me, I always think if something doesn't stand up on it's own merit and you have to actually put a description next to it, saying it's "evidenced based medicine" for people to vaguely take it seriously, then that's not a good sign... It's like they know that their theories are ridiculous, but hope if they label it, "not ridiculous science" then people will take it seriously. And to be fair, so far they do seem to be falling for it and taking it at face value.

 

Evidence based medicine is ranked medicine, ranked for likely reliability. Anecdotal evidence is on the ranking scale, but its the lowest rung. However as we know much of the "highest ranking, gold standard" stuff is still garbage science. Its not a perfect system and some groups play the system rather than do good science. For example, a meta-analysis can be severely biased by what studies get funded. Funding bias can severely skew the results.

On the flip-side, if someone has a dramatic improvement or worsening on some treatment, then N=1 be damned, its valid for that person or a coincidence. It cannot however be reliably generalised to the entire population.

One of the things I keep seeing about evidence based stuff is misleading statements like RCTs are the gold standard of evidence based medicine. Yeah, fools gold. If you add lots of qualifiers, like effective placebo controls for just one, then slowly the reliability improves. If, on the other hand, you introduce substandard methods like poorly designed or irrelevant subjective outcome measures, the reliability goes down.

Just for the record, with the huge number of failures in PACE, and downgrading it repeatedly for failure after failure, its no better than anecdotal evidence in reliability in my opinion.

 

EBM is similar to peer-reviewed, at least in terms of broad expectations for excellence.

I have a daughter who is a renowned academic. She is fond of both.

A patient, I have contempt for both.

Funny it can work that way sometimes.

 

Here is an extract from Sackett's article in BMJ on Evidence based medicine: what it is and what it isn't (1996)

 

Interesting to compare with the likes of PACE to see the difference.

Is the issue with the definition of EBM or the way "experts" abuse their credentials with impunity by attaching the label EBM to any old convenient piece of garbage?

I would suggest it's the deliberate attempts by "experts" to mislead or fail to do their job combined with the lack penalties for the offenders.

 

Basically there is evidence and "evidence". People twist the meaning to fit whatever it suits them to mean. You talk to a zealot about their obsession and they will come up with all manner of claptrap they believe is convincing evidence, and will unfortunately convince naive others. I think it maybe stems from the term "best evidence" which opens up the possibility of relying on completely crap evidence simply because any other evidence is even worse. Best evidence alone is not good enough, there needs to be a quality threshold below which it is simply unacceptable. Low quality "evidence" is not evidence at all, just garbage - especially when lives are at stake.

 

Franky, I would doubt the drafting skills of anyone who says "Evidence based medicine is..."

 

I was at a workshop given by our local Clinical Psychology service, a few years ago, at which the Head of Service kept going on about how a particular online therapy module that she was promoting was "evidence based", or rather "had an evidence base". So I checked it out and found the study. It was negative.

 

Yes. Prof Sir Roy Meadows springs to mind. Mothers, already suffering the loss of a child, then being blamed and incarcerated for it.

I remember watching a documentary about it and a pathologist who had also given court evidence in at least one case saying well, that her evidence was based on the evidence available at the time (or something similar). The interviewer was clearly giving her the chance to apologise for her role, but no. Despite not making it clear to the court that there may be limitations to the science, she obviously felt no regret or responsibility for her role.

 

It would be hilarious if it wasn't so serious. Citing evidence whilst neatly 'overlooking' to mention it was evidence of nothing, or even of failure.

 

This apparently quite small issue amongst the huge maze of issues, is actually at the heart of much of the problem with modern medical science I suspect. What should legitimately, legally, ethically, be acceptable as evidence, best or otherwise? Just trotting out the hackneyed phrase "best available evidence" should immediately flag up the need to provide sound justification for reliance on that evidence, beyond cosy patronage to beliefs and like-minded scientists, lazy assumptions, etc. It feels almost like rumour-led evidence. My dad used to use the expression "rotten to the core", and it feels applicable here unfortunately.

 

A difficulty seems to me to be that the word is used in completely different ways, sometimes within the space of a paragraph, without any thought as to the implications of the different usage or the ways in which the implications of one usage may be unwittingly carried over into a different usage.

 

Yes. The 'evidence' word and phrases are much misused and abused. The trouble is, it is a word that message-receivers immediately trust, and blindly assume must be trustworthy and can only be used if it is high quality evidence. Before I ever encountered this medical-world interpretation of evidence, I in my engineering world always understood it to mean what it should mean: high quality, highly reliable, fact-based indication of the truth about something. Here it just seems to often be a farcical parody of real evidence, to suit the politics and ambitions of those promoting it. It should be illegal, if only that were possible.

 

What people on this forum may not appreciate is the way many of the things we have fought for years are being rolled out for other diseases and are becoming mainstream. We know the promises are empty and the end result is blaming patients for their own ill health and/or making money out of them. The "Overcoming MS" system demands a complete change of diet and rigorous regime of exercise and supplements which not only promises the patient remission, but worse, claims their children will not get MS if they follow it which is a particularly nasty thing to do based on nothing except their anecdotal "evidence"

The BPS approach has learnt a lot from dealing with us and have convinced everyone it is a good thing. Just this morning I had an email about a questionnaire to be filled in (separately) by couples so they can see how relationships affect persistent pain. I can tell them the result now. Either pain exists while the relationship is good - enabling behaviour, or the relationship is bad and the stress is causing the pain.

Yet while everyone is excited about the BPS approach going to make them recover from MS or sort out their persistent pain they are not going to want to hear from us. Negativity will surely destroy everyone's chance of feeling good.

 

As I see it they typically do medical political rhetoric, rather than medical science. Its about persuading people in general, not developing sound data and showing how this explains things.