Discussion Board

Expand all | Collapse all

Diagnosis and chance

  • 1.  Diagnosis and chance

    Posted 15 days ago
      |   view attached
    In the attached paper, 'Diagnosis and chance', I point out that chance plays an important role at several places in the process of diagnosis in practice. I argue that issues raised by chance shape the method that is employed for diagnosis in practice to achieve high diagnostic accuracy in patients with varying presentations (prior probabilities) of a disease.
    The prescribed Bayesian method is not employed for diagnosis in practice as it does not engage with issues raised by chance in diagnosis.

    Bimal

    Bimal Jain MD
    Mass General Brigham/Salem Hospital
    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.

    Please note that this e-mail is not secure (encrypted).  If you do not wish to continue communication over unencrypted e-mail, please notify the sender of this message immediately.  Continuing to send or respond to e-mail after receiving this message means you understand and accept this risk and wish to continue to communicate over unencrypted e-mail. 

    Attachment(s)

    pdf
    Diagnosis and chance.pdf   142 KB 1 version


  • 2.  RE: Diagnosis and chance

    Posted 15 days ago
    I coud not open the file Bimal.

    Was that by chance or error?

    Rob Bell




  • 3.  RE: Diagnosis and chance

    Posted 14 days ago
      |   view attached
    Rob,
    I am sending you the PDF file again. Thanks.
    Bimal



    Attachment(s)

    pdf
    Diagnosis and chance.pdf   142 KB 1 version


  • 4.  RE: Diagnosis and chance

    Posted 15 days ago

    Bimal:

     

    I enjoy reading your briefs and especially this one.  I was introduced to this issue by one of my mentors, Dr. William S. Yamamoto, Chair of the Department of Clinical Engineering at the GWU Medical School in 1975 when I was working for him.  He introduced me to the concepts of cluster analysis and fuzzy logic as a potential means of resolving some of these issues or, at least illustrating them to clinicians when they were going through the diagnostic process.  He then moved back a step and introduced me to the concepts published soon after by Galen and Gambino in their book "Beyond Normal: The predictive value and efficiency of medical diagnoses" around the same time regarding Positive and Negative Predictive Value and how prevalence of a disease in a population will interact to yield unexpected and unwanted results.

     

    Later, I became a pathologist and personally witnessed this problem.  How laboratory tests are set up regarding cutoffs between "normal" and "abnormal" for, say creatinine or "no evidence of a myocardial infarct" versus "evidence of a myocardial infarct is present" for CKMB and now Troponin will greatly affect who is diagnosed with a disease and who is not.  This becomes a serious societal issue when we apply tests to screen large numbers of people who have no clinically evident disease even with tests stated to have 95% sensitivity and 95% specificity and I refer you to an excellent book titled "Over Diagnosis: Making People Sick in the Pursuit of Health" by Dr. H. Gilbert Welch.  I have personally seen and reported on this issue and refer you to my DEM 2016 poster: Slide 1 (manxenterprises.com) and DEM 2017 poster: Slide 2 (manxenterprises.com)

     

    Mark

     

    Mark Gusack, M.D.

    President

    MANX Enterprises, Ltd.

    304 521-1980

    www.manxenterprises.com