17 May 2009

Diagnosis is the key

There are not many articles in the Health Services Journal that set Dr Grumble alight. Management is pretty boring. But management is important which is why Dr Grumble keeps an eye on the HSJ just as they keep an eye on him. Managers often seem to get hold of the wrong end of the stick. Putting them right is a challenge. They come from a culture of suspicion - especially about doctors - so sometimes they just won't listen. Doctors who go into management are not always a solution to this problem. Doctors who choose to head for management are not necessarily the best individuals we have on offer and they tend to go native. Patients and quality of care quickly get forgotten. Spreadsheets and targets rule their day. And thinking goes out of the window. Too many managers, medical or otherwise, are like puppets on strings.

Perhaps that is why managers, medical and otherwise, want to turn clinical care into puppetry. Issue doctors with protocols and patient pathways, give them a few boxes to tick and problems will just disappear. That anyway is how managers think it should be done. But it is not as easy as that. Protocols may require, say, the correct interpretation of an X-ray and junior doctors required to follow the protocol may not be able to read the relevant radiograph accurately. Managers fail to grasp this. To them a broken bone is a broken bone. If a doctor can't see a fracture managers see that as odd. They will rectify the problem by sending the relevant staff on a half-day course to put right what is really a lack of experiential learning. But you cannot make up for lack of experience by going on a course. You can't tell a manager that. A broken bone is a broken bone. You can see it on an X-ray. They know that. The concept that it might actually be quite difficult and need a lot of practice escapes managers. They will tell you that practising medicine is like flying a plane. All you need is the right simulator.

Dr Grumble has often seen the wrong pathway followed because the diagnosis was wrong in the first place. This happens because diagnosis is not easy. If you have, say, a pain in the knee and the X-ray shows something wrong in the knee it may seem as if you are home and dry but it could be that the pain is actually a result of pathology in the hip. Even orthopaedics may not be straightforward. You don't want your knee replaced if the problem is in your hip.

On more that one occasion Dr Grumble has been asked by publishers to write a book - not on particular diseases but on symptoms. Instead of there being chapters on heart attacks or pulmonary embolism, there would be chapters on chest pain and breathlessness. Even publishers seem to understand that patients do not arrive at the GPs' surgery with pulmonary emboli - they come with breathlessness or some other symptom. Yet, if you look at standard textbooks, you will find plenty of good articles on pulmonary embolism or myocardial infarction and rather few on how to diagnose chest pain or breathlessness.

Goaded by his would-be publishers, Dr G has learned that surprisingly little is known about how doctors make diagnoses. Many of Dr Grumble's colleagues think that today's junior doctors are not as good as they were. Even the juniors themselves, worn down by MTAS and MMC, are beginning to believe this. It is nonsense. It is very difficult to recall what you once did not know. Experiential learning sinks in slowly. You carry it with you for ever and it is the key to diagnosis. Unlike some of his more arrogant colleagues, Dr Grumble can remember when as a junior doctor he would struggle to get to the nub of a patient's problem when the consultant seemed to be able to score a hole in one without even trying. Dr Grumble did this himself the other day with a case of mitral stenosis. A few seconds auscultation and, despite the near-by vacuum cleaner, Dr G was able to describe the tell-tale murmur and even made a few comments about the pre-systolic accentuation. You can't do this unless you have had experience. Few of Dr Grumble's junior doctors have heard such a murmur before. Often diagnosis is more subtle than a single physical sign but Dr Grumble can still, sometimes, find it easy to get there despite red herrings fed his way. Surprisingly, it seems that rather little is known about how experienced doctors are able to do this. The books say it is something to do with heuristics which seems to Dr Grumble to be a way of saying we don't know quite how it is done.

Given the importance of diagnosis, it is odd that there has not been more research on how it is we reach or fail to reach this crucial bottom line. Dr Grumble thinks it is for the same reason that Dr Grumble has, mostly, avoided writing book chapters focussing on symptoms rather than disease. He has done it and some lectures too but it is not easy if your audience is senior. Like most, Dr Grumble has tended put the topic of diagnosis into the too-difficult basket. The relative lack of research in this area probably has the same cause. It's just too difficult.

On the other hand Dr Grumble spends a long time with medical students trying to teach them how to reach a diagnosis or, better, a differential diagnosis. Diagnosis is what most of Dr Grumble's bedside teaching is about. An old lady falls over. The notes read 'impression: mechanical fall' because she tripped over a rug. There is no thinking here. No differential diagnosis. Dr Grumble has rugs at home. He has never fallen as a result. So when an old lady falls what could it be that has caused it? How do we find out? What things should we consider? Students don't always appreciate such teaching because you have to make them work. You have to get them to think on their feet. Any thinking will do. There are no right or wrong answers - though the students tend to think there are. The old lady could have fallen because she lost her glasses or because of postural hypotension or very many other things. The problem is considering all these possibilities and working out which it is.

So what is all this to do with the HSJ? It is that the HSJ has actually got a rather good article addressing the issue of diagnosis. The managers have at last realised how crucial this is. They have discovered that:

...... of 840 emergency admissions, revealed five (0.6 per cent) had been diagnosed incorrectly - all by junior doctors.

Dr Grumble would like to know more about this study because he doesn't think he performs anything like as well that. And it seems particularly surprising given that even in intensive care we are told:

.....one study found major diagnostic discrepancies at post-mortem in one in five patients who died on an intensive care unit.

Probably what this discrepancy shows is just how little we know about this topic. Dr Grumble has some awareness of his own deficiencies but he comes from an era when we did many more post mortems. Our bosses insisted on it because they knew that their diagnoses were often wrong and that they needed to know when they were wrong. These days we never find out just how wrong we were.

Anyway, the HSJ article is a good one and well worth a read.


Grumpy, M.D. said...

This is an iffy issue, and one that remains a serious one even in our age of high-tech gadgets and scans.

I agree with you- management and pathways and protocols are sometimes semi-useful guidelines, but are NEVER a good substitute for a good clinician.

The thinking process that goes into this is hard to characterize. Experience, exam findings, objective test data, etc, but there is also a degree of "gut feeling" and even luck.

Jobbing Doctor said...

I'm sorry to make a 'Grumpy' triumvirate, but I do agree with you both. The area where diagnosis is more tricky is primary care, where you don't already have the stuff pre-filtered as you do in hospital.

I teach my students that diagnosis is 80% hisory, 10% examination and 10% investigation. modern medicine seems to demand the reverse.


Dr Grumble said...

I agree with your proportions, JD. And your comment about modern medicine.

This is another thing that the managers don't seem to understand. They seem to want every scanner there is instantly available in the GP's polyclinic as if that is the key to diagnosis in primary care.

Dr Aust said...

Mrs Dr Aust would agree with you, Dr G. She has a line something like:

"If I had a bottle of champagne for every little old lady that came in with a fall who we finally diagnosed as having had an arrhythmia or a silent MI I'd have a cellar."

- the point being that too often it was assumed (esp by jr. A&E and ortho folk) that all 70+ yr old ladies simply tripped over things and fell down. Mrs Dr A used to try to explain that the key was whether the lady had a reason to fall down, and that taking a proper history - largely to work out how fit and active and healthy (or not) - and thus likely to fall (or not)- the LOL was.

Apart from in general medicine, she used to see the same "LOL fall fallacy" turning up pre-op in anaesthesia, where the LOL would be on the list for an emergency op to fix the broken bone w/out anyone having really asked why she fell in the first place.

Dr John Crippen said...

Interesting article but possibly indicative of a worrying underlying trend. It is entirely par for the course, but as misguided as ever, that a hospital consultant should be asked to write book about presenting symptomatology. By the time the punter gets to hospital he has either been screened by a GP or self-screened by perceived urgency. Not to suggest that there are not diagnostic challenges on the front line of the hospital. Of course there are.

But GPs frequently see diseases so early in their evolution that the standard medical texts are unhelpful. You rely on all sorts of clues. Personal knowledge of the patient : Mrs Bloggins has never presented with a persistent cough before so, although there are no signs, she DOES need a CXR. My favourite is the heavy smoker who you have known for years and whom you have unsuccessfully tried to persuade to stop smoking. One day he presents saying he wants "a check up" - no specific symptoms, no cough, no haemoptysis, no weight loss...but it emerges that he stopped smoking six weeks ago. It's lung cancer until proved otherwise. And so we can go on for ever and a day about the art of general practice rather than the science.

Do GPs miss diagnoses on first presentation? Hell, yes, all the time. But we safety net, and bring them back and review, and usually get it the second time. Except that these days some of them have taken themselves to A & E where the diagnosis, now apparent, is made, and a junior doctor or nurse raises eyebrows when the patient asks why his own doctor did not make the diagnosis.

In general practice, time is our friend and our enemy. Time - a few days - for something to develop and of course, occasionally, time still to miss something.

Do I need a protocol, a list of 27 diagnoses for each symptom? No thanks. This is what the pharmacists have started to play with, and it's a nightmare.

Would I like immediate same day access to CT and MRi? Sure. Who would not? Where I work, I don't have ANY access to CT and MRI. Would it improve my diagnostic success rate? Possibly. Not sure.

Would it change the nature of my job. Yes it would. Totally. It would move me gradually from being a diagnostician, skilled at picking up disease early in its evolution, to being a protocol monkey. Maybe that is best. That is certainly where we are headed for, make no mistake. Once the primary care "clinicians" (I use that word in the way the Jobbing Doctor understands) take over that will be all he can offer.

Just before Xmas a lady presented saying that she was feeling non-specifically unwell but the only thing she had noticed was that, when she was speaking, after about three sentences, her speech became slurred. And it did. I tested it. Could not otherwise convince myself of inappropriate muscle tiring, but on this history you have to exclude Myasthenia gravis. Did the test. It was positive. Referred her to the local neurologist (nice chap) and got letter back saying "must congratulate you on your diagnostic acumen". How charming, you may say. Passed it round the partners at coffee, and they all reached for the white telephone. He meant well, but it's bollocks. Not an appropriate thing for him to say. I would not ever write to him and congratulate him on his diagnostic acumen. I would not patronise him like that, and we do not expect him to patronise us. Early diagnosis is what we do. It's nice to get it first time.

I would like to see more of the data on misdiagnosis in general practice. Are we talking of comparing final correct diagnosis with tentative diagnosis made on first presentation to the GP? I would like to see a trial on final diagnosis compared to the first two weeks of presentation in general practice.

Example : change in bowel habit should be investigated in the middle aged. I read that on the back of a match box somewhere, so it must be true. But what is a "significant" change in bowel habit?

A fifty eight year old comes back from Egypt with diarrhoea which has persisted for nearly a week. Not unwell. No blood. He sees the GP 3 times over next four weeks; first time, general advice, second time stool culture (negative), third time occult bloods X 3, two negative one positive. PR normal. No weight loss. Not anaemic. Tumour markers normal. No family history. Referred to colorectal clinic (NOT TWR as he does not meet the criteria). Seen six weeks later by Colorectal Nurse who does a sigmoidoscopy (normal) and decides to order a barium enema. This is done 4 weeks later. It shows a carcinoma in the upper part of the descending colon.

Patient blamed GP for not making the diagnosis sooner and made a formal complaint, which he pursued vigourously with lawyers. Complaint was thrown out, but it was six months stress for my partner and for the whole practice.

That's a real story that happened to one of my partner's and his patient.

Bet that would show in the survey as delayed diagnosis? And it is a delayed diagnosis. BUT, is it culpable delay, or is it merely part of life's great tapestry. If you are to say there was fault, then that's fine by me. We will do a TWR referral on every case of diarrhoea presenting in anyone over the age of forty. How, then, will we deal with the queues outside the colo-rectal clinics?

Answers on a postcard to Lord Darzi.


Phew! What a long comment. I was typing away half watching the increasingly lovely Dr Alice Roberts sledging in Siberia.

sam said...

'diarrhoea which has persisted for nearly a week, not unwell'

Shouldn't the fact that this patient was 'well' prompted the GP to speed up the investigations Dr C? Especially because he's just been to Egypt, or a hot country hence Diarrhoea will always be accompanied with being unwell because such condition is 'always' microbial?

While I can understand your partner is not used to such cases because of the different climate, an Egyptian doc would've picked it straight away ... because they've seen 'it' many times before ... and no queues at the colorctal clinic would have been neccessary .. or sending postcards to Lord D either because I am sure he is aware of this dilemma :-)

Jobbing Doctor said...

What do you suggest, Sam?

Refer all patients with diarrhoea for a week who have been to Egypt? What about the risks of sigmoidoscopy and Barium Enema?

No, this is not a swipe at Lord D, as he doesn't see the mass of patients with Diarrhoea, it is just that Dr C's partner did everything right, but things don't always present logically or predictably.

I find dealing with bowel symptoms in over 40s very hard to assess.

Dr C. Get CT and MRI for your patch: it has transformed my management of back pain, knee problems and headaches.

Dr Grumble said...

Mrs Grumble had a book (we probably still have it somewhere) written by a GP which started with the symptom. She rarely opened it. I looked at it many years ago and thought it was remarkably useless. It failed to get across any of the nuances in diagnosis some of which you mention, Dr C. It is very difficult to do this in a book. That is the reason why so few of use have taken on the challenge to either write books on or research how it is we reach a diagnosis.

Patients think a diagnosis is either right or wrong but really it is a hunch based on probabilities. It should be reviewed as time passes. Even Dr C talks about ‘missing diagnoses’ as if he has done some wrong but these are not errors. No computer could put you right. Quite often there simply is not enough information to get to a diagnosis and, contrary to what many may think, lots of tests are unlikely to help and could be counterproductive.

My own feeling is that the way we get to a diagnosis is to do with very high level thinking that experienced humans can be good at but computers, at present anyway, are not. It would be nice to understand it a bit better but it is very difficult because it involves integrating all those very many things we know about a patient just some of which Dr C mentions.

Cockroach Catcher said...

Managers forget that we have protocols all along, it is called medical training and the most important part of it is the apprenticeship whether we still like to call it that or not. The human mind works better (for now) than the best computer. We sometimes pick up clues when we see a patient that may not be obvious in a tick box scenario and we may by pass several steps in the “flow-chart” to reach a diagnosis or a list of differential diagnosis to then set up investigations. Even in psychiatry, two overdoses might have totally different management although they took the same number of tablets. If we are allowed to continue we save them money and we hopefully do not over investigate.

That is why we need all that memory work so that the brain works on parallel processing and yet too many now rely on the computer to do that. The day will come when the ward round is carried out with an iPod, just like judges in the courts with their computer screens (yes, that is what they do now). One day lawyers too need not reel off quotes of cases by heart.

The Cockroach Catcher

Anonymous said...

Thank you for such an informative and thought provoking blog.

Get the book written -you have an excellent writing style. I'm sure that plenty of GPs will collaborate.

Dr John Crippen said...



Gawd, Sam, just about EVERYONE who goes to Egypt comes back with diarrhoea. It's the worst country in the world for it. And, beleive it or not, NOT everyone with travellers diarrhoea is particularly unwell. I daresay if he had been to an Egytian doctor he would have had a grand slam of treatment, probably with ciprofloxain, but that is not really appropriate.

If you are saying that the Egyptian doc would have instantly diagnoed Ca Colon...well, I think that is unlikely.

I susect that this chap DID have a non bacterial travellers diarrhoea and also happened to have another problem


Dr John Crippen said...



Sure. Great stuff on chest problems. But, actually, how does a chest physician start on the early presentation of, say, gynaecological problmes?


sam said...


I don't know JD about refering 'all' JD, what I know is that if the patient has been presenting with a diarrhoea for a 'full' week but is well and no other symptoms, then the doc should have suspected other reasons than Egypt being the cause. That the doc did not, shows 'his' limitations and the patient is right to question his judgement to delay tests.

sam said...


I'll take your 'expert' word for it Dr C but .. does that mean the doc should therefore assume 'all he sees is sand' and allow a patient, who is otherwise well, to go for a 'whole month' without having an 'in your face' symptom like diarrhoea to go unchecked?! Pretty naive .. and incompetent if you ask me ...

Dr Grumble said...

I shan't be writing the book. Not on diagnosis anyway. It is just too difficult.

We have an example in these comments of just how difficult it is to get across the distinction between reasonable diagnostic delay and unreasonable diagnostic delay.

There is no point in speeding up diagnosis unless it alters the outcome. Many cancers have been present for years before they manifest themselves so, if you want to criticise, when it comes to bowel cancer the main problem is in not diagnosing the problem before there are any symptoms and that requires screening which is only now becoming available and is a system not individual doctor failure.

Dr Grumble said...

You know my Achilles' heel, Dr C! Actually if you take, for example, the symptom of cough you will find whole papers written on this particulat topic - by chest physicians rather than GPs. My impression is that GPs see this symptom from a completely different angle - presumably because they see lots of acute coughs that go away with or without treatment. Chest physicians see the more mysterious coughs that have defeated the GP - but perhaps not all GPs.

Dr Fostes said...

diagnosis is 80% hisory,...very true jobbing doctor

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