Sunday, February 01, 2015

Cookbook medicine

This was a criticism levelled at evidence based medicine, when it became a way of thinking some years ago.  The criticism was that your doctor would diagnose you, and then look up what to do and do just that.  There was no place for expertise or experience.   

Present day diagrams of evidence based medicine include, of course, professional expertise and patient experience, as well as the research evidence. 

I don't think that was ever a fair criticism, but having had a head injury in September (I fell off my bike), and been in receipt of doctors' advice, I think it misses the point. 

The diagnosis may not be easy.  And the evidence may be difficult to find, and when you have found more than one piece of evidence, you may have more than one recommendation.  

Following my accident, the DVLA told me I must stop driving.  I had reported the accident in late September, and they told me this in mid January.  This was because I am at an increased risk of a seizure, as a consequence of the head injury.  This is the guidance of their medical panel.

However, after I was declared fit for work, and while I was waiting to hear from the DVLA, I asked my GP for advice (the DVLA recommend this, while you are waiting).  They felt I was ok to drive.  They examined me, read my notes, and talked to me (the DVLA had only been able to do the second of those), and they knew what the DVLA would be worrying about and felt I was at low enough risk.   

Why the difference?   Was someone not applying the evidence alongside the patient experience and their own expertise?  Was someone living by the cookbook method and the other one not?  Was there something wrong with the cookbook?

What does a medical librarian do when faced with a health problem?  That's right, they do a literature search. 

Guidelines do seem to agree that having a head injury makes you more at risk of a seizure.  They don't, however, quantify the risk, and they don't seem to talk about any other factors that might increase the risk.   So I searched Medline.

And that is what made me think of the second and third of my reasons.

Was it a head injury, or a brain injury?   The MeSH term Craniocerebral trauma/ covers them all, but is that too broad?  And are we talking about Epilepsy as the complication, or Seizures?   Several articles I found did indeed say that head trauma (another possible search term!) did leave you at increased risk of epilepsy, but maybe for a year, not six months, and maybe much longer.  It does not seem to be clear cut.

A textbook I found said that a seizure at the scene might actually not count as epilepsy, and that there is also an issue with who observed it.  If it was someone who had come to help, they might think it was a seizure when it was not.  I wouldn't know the difference, I am sure, and would probably tell the paramedics that I had seen a seizure.  But what if your helpers were health professionals and actually knew?

And was it a mild head injury or a serious one?   This might depend on the definitions in the paper you are reading, but is there an agreed set of definitions?

So, no cookbook medicine.

Even if the diagnosis was straightforward (seizure or not, mild or serious injury...?), finding the evidence is not, and reconciling it with other evidence is not either (is "post traumatic epilepsy" the same as a post traumatic seizure, why do different studies report different risks...?).   There is a need for the expertise of the professional alongside the evidence and knowledge of the experience of the patient.

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