Discussion Board

Expand all | Collapse all

Heuristics in diagnosis

  • 1.  Heuristics in diagnosis

    Posted 02-07-2021 11:16
      |   view attached
    I am attaching a paper I wrote recently on role of heuristics in diagnosis for review and comments.
    I point out the notion of heuristics as a source of diagnostic errors is based entirely on the studies of Tversky and Kahneman who found that subjects make faulty probability judgments from given information by neglecting important probability rules due to influence of heuristics.
    But when we analyze the process of diagnosis in practice, we find physicians do not make probability judgments (diagnose) from presentations. Instead, they suspect a disease from a presentation, formulate it as a hypothesis and diagnose it only if the hypothesis is verified to be correct by tests.
    But this process of hypothesis generation and verification which occurs in diagnosis in practice is not a part of Tversky and Kahneman's version of heuristic reasoning. Therefore, I suggest, their version of role of heuristics is not applicable to diagnosis.
    I point out that a heuristic plays an essential role in generation of a hypothesis without which diagnosis is not possible.
    We may need to alter our view about the role of heuristics in diagnosis.
    Thanks.

    Bimal

    Bimal Jain MD
    Northshore Medical Center
    Salem MA 01970. 
    The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Mass General Brigham Compliance HelpLine at http://www.massgeneralbrigham.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.


  • 2.  RE: Heuristics in diagnosis

    Posted 02-08-2021 13:41
    I was interested in Bimal Jain's post about heuristic thinking.

    I know little about the topic. I heard nothing at all about heuristic thinking in Med School and training.

    How important is it in diagnosis?

    What kinds of heuristic thinking are there?

    Are there different kinds that lead to greater accuracy or greater inaccuracy?

    What kinds are more effective in diagnosis?

    Is heuristic accuracy related to SAT scores?

    Can you unlearn faulty heuristic thinking?

    And what is faulty?

    Are there any people that should not be diagnostic physicians by virtue of their heuristic error thinking?

    there are no birds in my back yard, I assume the bird feeder is empty?

    Etc. Etc. Etc. 

    Rob Bell, M.D.





  • 3.  RE: Heuristics in diagnosis

    Posted 02-08-2021 16:23
      |   view attached
    Robert Bell
    Feb 8, 2021 1:41 PM
    Robert Bell
    I was interested in Bimal Jain's post about heuristic thinking.
    More accurately, it should be 'heuristic decision making' because very little, if any, thinking goes into heuristics. Most heuristics are unconscious and don't reach a level of deliberation that could be called 'thinking.'

    I know little about the topic. I heard nothing at all about heuristic thinking in Med School and training.
    You are not alone. Most current practicing physicians have had little training in what heuristics are, what they do, and what the consequences of indiscriminate use may be. 

    How important is it in diagnosis?
    Critically important given their association with cognitive biases

    What kinds of heuristic thinking are there?
    Heuristic decision making dominates most of what we do. In everyday life, probably about 95%. So, all kinds.

    Are there different kinds that lead to greater accuracy or greater inaccuracy?
    Most of them work well most of the time, but not all of the time.

    What kinds are more effective in diagnosis?
    They are good for generating ideas and possibilities In diagnosis, so the effective ones are the kinds  the decision maker is aware of and can modify, if necessary

    Is heuristic accuracy related to SAT scores?
    Firstly, SAT scores are related to ability to reason.  'Heuristic accuracy' would presumably depend on the decision maker detecting that an heuristic had been used,  has reflected on what it has predicted and if his/her response needs calibrating or not, which would include determining if it is biased or not. Given  that cognitive scientists measure rationality (ability to reason effectively) in terms of a decision maker's vulnerability to bias,  one would think that well-calibrated (effectively used) heuristics would be related to SAT scores.

    Can you unlearn faulty heuristic thinking?
    There is strong evidence that decision making that is faulty due to heuristics associated with cognitive bias can be un-learned through  training - the area of CBM (cognitive Bias Mitigation) - see attached..

    And what is faulty?
    Many heuristics are highly effective. Faulty is when the heuristic fails, as shortcuts eventually do.

    Are there any people that should not be diagnostic physicians by virtue of their heuristic error thinking?
    Given that most of us spend most of the time making heuristic decisions, there wouldn't be many of us left if we disqualified those who use heuristics to make decisions. If one uses heuristics indiscriminately (without metacognitive strategies such as reflection and mindfulness) then we would not be well calibrated decision makers, and probably shouldn't be engaging in the critical activity of diagnosing disease.

    there are no birds in my back yard, I assume the bird feeder is empty?
    That's a good example of a heuristic that, if uncalibrated, might lead to an erroneous assumption. It might be that a major bird of prey is nearby and your regular patrons are unwilling to take the risk. 

    Etc. Etc. Etc. 

    Rob Bell, M.D
    Pat Croskerry



    Attachment(s)

    pdf
    DITS Ch 15 Pat edits.pdf   1.52 MB 1 version


  • 4.  RE: Heuristics in diagnosis

    Posted 02-08-2021 18:54
    I finally get it! Great questions. Great answers. Thanks.

    Charles A. Pilcher MD FACEP
    Editor, Medical Malpractice Insights - Learning from Lawsuits
    medmalinsights@gmail.com
    Kirkland, Washington
    206-915-8593






  • 5.  RE: Heuristics in diagnosis

    Posted 02-09-2021 09:15

     

     

    February 9, 2021

    8:57 AM

    So, you bring out a very, very important factor in achieving a correct diagnosis - " metacognitive strategies such as reflection and mindfulness".  No matter how a clinician reaches a diagnosis, willingness to challenge ones own conclusions is paramount to considering all the issues and options.

     

    Again, all of the true experts in any vocation go through this process constantly, with and without the diagnostic team.

     

       Nelson Toussaint

     

    TAMARAC LLC

    860-844-0199

    ntoussaint@tamarac.com

     






  • 6.  RE: Heuristics in diagnosis

    Posted 02-09-2021 11:57
    Is that is why questions are so vital in diagnostic accuracy - to ones self or others.

    Do Questions break through the built in responses?

    There is a lot of recent discussion about conspiracy theories, could that also be related to heuristic decision making?

    It seems to be related to something that is is very hard to change.

    Are our standard heuristic decision making processes hard to change?

    Just a thought!

    No birds and no food in the feeder. Have not seen a hawk!

    Rob Bell,




  • 7.  RE: Heuristics in diagnosis

    Posted 02-09-2021 11:30
    A heuristic, which is a mental shortcut, plays a very different role in diagnosis than it does in daily life. In daily life, a heuristic leads to a judgment being made from initially available information such as a birdfeeder being empty when there are no birds in backyard. This judgment may or may not be correct. In diagnosis, on the other hand, a judgment (diagnosis) is almost never made from a presentation (initially available information). For example, acute MI is not diagnosed from chest pain in a patient. Instead, this presentation leads to acute MI being suspected due to the heuristic of resemblance and formulated as a  hypothesis which is evaluated by a test. The test results in the hypothesis being correct or not; then  acute MI is ruled in or ruled  out.
    Thus while a heuristic may lead to an error in judgment in daily life, it does not lead to an error in diagnosis due to the hypothesis generation and verification method. It is unfortunate that the error prone results of Tversky and Kahneman's studies on heuristics in daily life have been applied to diagnosis to conclude they are a source of diagnostic errors. In reality, a heuristic is employed in diagnosis like it is employed in science which is to generate a hypothesis that is always evaluated by an experiment or test. Thus it plays an essential role in diagnosis in generating a hypothesis without which diagnosis is not possible.





  • 8.  RE: Heuristics in diagnosis

    Posted 02-09-2021 12:01

    In some pediatric conditions, heuristics serve as a reliable way to diagnose patients without formal hypothesis testing or obtain diagnostic studies. Two examples come readily to mind.

     

    1. 2 AM, November, a crying toddler is carried past the physician workstation exhibiting a barky cough, stridor at rest and suprasternal retractions and his triage vitals show a fever, tachypnea, normal sats and only mildly elevated HR. The heuristic representativeness restraint (if looks, quacks and flies like a duck it's a duck) allows the pediatric ED physician to place orders for racemic epi neb and dexamethasone with this initial information and without having to take a history, or do more of an exam than is described above. The likelihood that the peds ED doc is right is very high because 1) few other conditions present in this way 2) immunization rates for Haemophilus influenza b are so high that the epiglottitis has virtually disappeared from the map. Indeed, I have seen children just like this present to non-peds EDs and have unnecessary neck radiographs obtained and then misinterpreted by non-peds radiologists as epiglottitis prompting unnecessary antibiotics and helicopter critical care transport to a peds hospital. The hypothesis generation and "rule out" strategy was more dangerous to the patient than reliance on heuristics. Of course, one should ask about FB aspiration and immunization status because a heuristic diagnosis without checking off a few other boxes could get one into trouble.
    2. A 5 y/o boy presents with concerns of rash only on his legs, mild abdominal , ankle and wrist pain and mild swelling of his legs. His VS are all normal for age. The clinician "search satisfies" when the exam reveals palpable purpura and petechiae restricted to the BLE and she diagnoses Henoch Schoenlein Purpura. At minimum a UA should be obtained to identify signs of nephritis and, if found, perhaps a renal function panel to identify signs of AKI. Yet, no hypothesis or differential is likely to be of use to the seasoned clinician in this case and, indeed, doing an exhaustive search for other causes of purpura (say ITP, meningococcemia) to test the hypothesis very well places the patient at risk of complications of the hypothesis testing (e.g. false + blood culture leading to admission and unnecessary antibiotics).

     

    I find that, similar to comments made by Geoff Norman and colleagues (McLaughlin, Eva & Norman. Reexamining our bias against heuristics. Adv in Health Sci Educ (2014) 19:457–464), "under certain circumstances using heuristics may lead to better decisions than formal analysis." Yet, I have also fallen prey to diagnosis momentum and confirmation bias as I mentioned in another recent post about missing a case of Guillain-Barre. There is a place in medicine for both intuitive diagnosis and more analytic reasoning. Both are prone to error under certain conditions. To say one is better than the other misrepresents the nuance of the diagnostic process.

     

    signature_1232185625

    Joe Grubenhoff, MD, MSCS (he/him/his) | Associate Professor of Pediatrics 

    Section of Emergency Medicine | University of Colorado

    Medical Director – Diagnostic Safety Program

    Children's Hospital Colorado

    13123 East 16th Avenue, Box 251  |  Anschutz Medical Campus  |  Aurora, CO 80045 | Phone: (303) 724-2581 | Fax: (720) 777-7317

    joe.grubenhoff@childrenscolorado.org

    Connect with Children's Hospital Colorado on Facebook and Twitter

    signature_829143088

    For a child's sake...

                    We are a caring community called to honor the sacred trust of our patients, families and each other through

                    humble expertise, generous service and boundless creativity.

    ...This is the moment.

     


    CONFIDENTIALITY NOTICE:  This e-mail, including any attachments, is for the sole use of Childrens Hospital Colorado and the intended recipient(s). It may contain confidential and privileged information or may otherwise be protected by law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message and any attachment thereto.






  • 9.  RE: Heuristics in diagnosis

    Posted 02-09-2021 13:30
      |   view attached

    Hi everyone,


    I just read the attached paper - it was just published today online ahead of print, in the journal Radiology I thought it would be of high interest to members of this list-serve and to the SIDM community.  You will undoubtedly recognize their Figure #1!


    In this brand-new paper, hot of the press today, Dr. Steven Waite, a radiologist at SUNY-Downstate in Brooklyn and colleagues review and comment on the problem of racial disparities in radiology image utilization.  Of course, radiology imaging is only one piece of the diagnostic process, but it is gaining in utilization and importance.


    In this group we have previously discussed the imperative of appropriate imaging utilization in the context of over-utilization, which is a recognized problem leding to significant risk of misdiagnosis/over-diagnosis for patients (among other risks).  This paper highlights the opposite problem, namely the underutilization of imaging, and explores the question as to what expent disparities remain in imaging utilization which might track with ethnicity/race and not only with S.E.S.  I think it is another important part of the conversation.


    All the best,


    Mike



    Michael A. Bruno, M.D., M.S., F.A.C.R.   
    Professor of Radiology & Medicine

    Vice Chair for Quality & Patient Safety

    Chief, Division of Emergency Radiology

    Penn State Milton S. Hershey Medical Center
    ( (717) 531-8703  |  6 (717) 531-5737

    * mbruno@pennstatehealth.psu.edu  

    1571679014277






  • 10.  RE: Heuristics in diagnosis

    Posted 02-09-2021 17:31

    Medicine is a very human endeavor. Three points need to be appreciated in response to Dr. Jain's comments. 1) Since the 1950s many studies have examined physician judgments including diagnosis. Over the past 40 years many studies of physicians have been performed from the perspective of the use of heuristics and bias (H&B).  As is clear from the results of these studies, we don't get a pass from the foibles of human judgement, decision making, and learning from our practice of medicine simply because we've been trained as physicians. 2) We have no perfect tests. The assessment of prior probabilities (clearly necessary to interpret test results) can be jaded by several H&Bs. 3) Overconfidence is a persistent finding of physician judgments and decision making. The 2 citations provide (A) an overview of H&B from a medical perspective and (B) a randomized trial examining judgments in a standard source of learning experience in medicine (B). A and B are simply convenient examples. A large literature exists on the subject of H&B in medical judgments and decision making including excellent summaries by Dr. Crosskerry. Physicians are not a special subset of human beings when it comes to the effects of H&B on judgments, decision making and learning. A) Systematic Errors in Medical Decision Making: Judgment Limitations NEAL V. DAWSON, MD, HAL R. ABKES, PhD J Gen Intern Med 1987; 2:183-7. B) Hindsight Bias: An Impediment to Accurate Probability Estimation in Clinicopathologic Conferences. NEAL V. DAWSON, MD, HAL R. ARKES, PhD, CARL SICILIANO, BA, RICHARD BLINKHORN, MD, MARK LAKSHMANAN, MD, MARY PETRELLI, MD (Med Decis Making 8:259-264, 1988) Online version: http://mdm.sagepub.com/content/8/4/259



    ------------------------------
    Neal Dawson
    Case Western Reserve University
    ------------------------------



  • 11.  RE: Heuristics in diagnosis

    Posted 02-10-2021 08:17

    Thanks, Neal - excellent summary and resources.


    Mike




    Michael A. Bruno, M.D., M.S., F.A.C.R.  
    Professor of Radiology & Medicine

    Vice Chair for Quality & Patient Safety

    Chief, Division of Emergency Radiology

    Penn State Milton S. Hershey Medical Center
    ( (717) 531-8703  |  6 (717) 531-5737

    * mbruno@pennstatehealth.psu.edu  

    1571679014277