Role of diagnosis in cutting waste in clinical care

Wed Nov 12 15:47:11 UTC 2014

Your comment about always coming back to the basics taught a 100 years ago  reminds me of some lines from the poet T.S. Eliot
                                                  We shall not cease from exploration
                                                   and the end of all our exploring will be to
                                                    arrive where we started and know the
                                                    place for the first time.

I believe concern about not everybody being a skilled diagnostician is exaggerated. After all, health care workers all over the world diagnose with 85 percent accuracy on a daily basis.
Improvement in diagnostic ability will occur, I suggest, when we have a better understanding of the process of diagnosis which will be gained by careful study and analysis of diagnosis as it is performed in actual practice as well as in published CPCs and clinical problem solving exercises.
Here are some of my thoughts on diagnosis:

1.       Diagnosis, which is determination of a disease in a patient with symptoms, is essentially a problem solving activity, which is no different than other problem solving activities, for example, detective work in solving a crime.

2.       The problem in diagnosis is furnished by a patient's symptoms in actual practice and by given data in a CPC.

3.       If the symptoms are highly typical such as intermittent wheezing and dispend in a young person with multiple allergies, the disease asthma is diagnosed rapidly as the symptoms are practically a description of this disease.

4.       It is when symptoms or given data are atypical or complex that we need to adopt a deliberate strategy to determine the disease.

5.       This strategy consists of, as I pointed out in my analysis of CPCs of first identifying key features in given data.

6.       The next and extremely important step is to perform an exhaustive differential diagnosis, that is, list all possible diseases which if present, could explain the key features. This list needs to include diseases that  are common as well as uncommon given the presentation as it is often impossible to know which disease is present in the given individual patient without further testing.

7.       It is only by evaluating each disease in the differential one by one, as is done in CPCs that we can ascertain which disease is actually present.

8.       The reason a differential diagnosis is not performed  more often is the belief, I suggest that the presentation is some sort of evidence for a particular disease. Could the cognitive bias of representativeness be playing a role here?

9.       The correct approach which would promote constructing a differential diagnosis is to look upon a presentation as a problem in which the key features function as clues to various diseases.
I look forward to your response to these thoughts.


Bimal P Jain MD
North Shore Medical Center
Lynn MA 01904

From: Jason Maude [mailto:Jason.Maude at]
Sent: Friday, November 07, 2014 12:54 PM
Subject: Re: Role of diagnosis in cutting waste in clinical care

It's amazing how it always comes back to the basics that were taught a 100 years ago! I am a firm believer that the differential is a great mechanism to trigger and promote good thinking and, thereby, better diagnosis.

I absolutely agree that the CPC cases are incredibly useful and is one of the main reasons why we have used them for the last 10 years to test Isabel against and help improve it.

An interesting point from this thread is how it has been highlighted that not everybody can be a skilled diagnostician. However, there has been some very interesting work done in chess showing how even average players using a computer program can become very good players and match a grand master which has useful parallels for medicine and this discussion.

One of the most valuable aspects of diagnostic decision support systems (DDSS), from a whole health system view, is how they can help make all clinicians significantly better at diagnosis than they are already.  In fact 3 medical schools (Rosalind Franklin, Columbia and Rocky Vista) have now done studies which show that a DDSS (in these cases Isabel) has significantly increased the diagnostic accuracy of their students.

Best wishes

Jason Maude
Founder and CEO Isabel Healthcare
Tel: +44 1428 644886
Tel: +1 703 879 1890<>

From: <Jain>, "<Bimal P.>", "M.D." <BJAIN at PARTNERS.ORG<mailto:BJAIN at PARTNERS.ORG>>
Date: Friday, 7 November 2014 13:53
Subject: RE: Role of diagnosis in cutting waste in clinical care

To answer your question  'how do you make our current clinicians  skilled diagnosticians' it would be helpful to know how existing skilled diagnosticians diagnose.
We would all agree, I think, that physicians who discuss CPCs in New England Journal of Medicine qualify as skilled diagnosticians. For the past few weeks, I have been analyzing 50 consecutive CPCs published in NEJM from September 2013 to October 2014 to learn how these physicians diagnose. My analysis is not yet complete but here are some preliminary findings.

1.      In 20 CPCs, the diagnosis was known beforehand to the discussing physician and 4 CPCs were primarily about management issues (e.g. of trauma after Boston Marathon bombing). Therefore I exclude these 24 CPCs and limit my analysis to the remaining 26 CPCs.

2.      In all 26 CPCs, the following three steps were taken in sequence by the discussing physician to reach his diagnosis

(a)    The given data(symptoms, signs lab tests, course) were carefully studied and summarized in a few sentences highlighting a few key features.

(b)   These key features were employed to construct an exhaustive differential diagnosis which include all possible diseases which could explain these features.

(c)    The known characteristics (from textbooks, journals, experience) of each disease in the differential diagnosis were compared with those actually  present in the given patient.
By this process of comparison, diseases were eliminated one by one, till one was chosen as the most likely diagnosis.

3.      Amazingly, the most likely diagnosis given by the discussing physician was confirmed to be correct by the pathologist when he presented a highly informative test result in all 26 CPCs.

4.      There are obvious differences between diagnosis in these CPCs and diagnosis in actual practice such as

(a)    Data are given to a physician in a CPC, weeks to months in advance, while we diagnose in actual practice on the spot in real time when we encounter a patient.

(b)   In a CPC, a lot of data are given to a physician all at once, while in actual practice we get data in bits and pieces starting with symptoms only in the history given by a patient.

(c)    As a CPC is a teaching exercise, it is set up somewhat as a game. The discussing physician arrives at his likely diagnosis by a process of elimination as he is not given the highly informative test result which would diagnose it definitively.

In actual practice, we test the most likely disease first of all as we want to diagnose it definitively soon so that we can start treatment for it.

5.      It is of interest the notion of probability did not play any role at all during diagnosis in these 26 CPCs. In fact, the term ' probability' was mentioned only once in all 26 CPCs and that too in reference to treatment.

6.      Despite these differences, there are important lessons to be learnt for diagnosis in actual practice from diagnosis in CPCs as follows:

(a)    The importance of identifying key features in given data

(b)   The importance of constructing exhaustive differential diagnosis

(c)    The importance of evaluating all diseases in differential till one is diagnosed definitively.

I hope you find this analysis helpful.



Bimal P Jain MD
Pulmonary-Critical Care
North Shore Medical Center
Lynn MA 01904

From: Jason Maude [mailto:Jason.Maude at ISABELHEALTHCARE.COM]
Sent: Thursday, November 06, 2014 12:22 PM
Subject: [IMPROVEDX] Role of diagnosis in cutting waste in clinical care

You may all be interested to see a paper just published by the Academy of Medical Royal Colleges in the UK entitled "Protecting resources, promoting value:

a doctor's guide to cutting waste in clinical care"

My favourite part is on P20 where it states so perfectly:

"Fundamental attributes of a value-promoting doctor

A skilled diagnostician:

forms intelligent differential diagnoses and can discern which investigations are truly necessary to diagnose and treat the patient effectively."

The key question is how do you (practically) make our current clinicians "skilled diagnosticians" (those that aren't already of course)?


Jason Maude
Founder and CEO Isabel Healthcare
Tel: +44 1428 644886
Tel: +1 703 879 1890<>



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