Diagnosis gone awry: A flawed drug test could be sending thousands of innocent people to jail each year

Regan, Elizabeth ReganE at NJHEALTH.ORG
Tue Jul 12 22:33:28 UTC 2016


I agree that this story is not about medical diagnosis per se, but does raise some important issue around medical diagnosis.

With the trend to algorithms driving medical decision making – especially with mid-level providers, I believe that there is an inappropriate assumption that a test result is “positive” or “negative” and that this in turn drives a message to the patient that they do or do not have “disease X”.  This is fostered by specialists talking to primary care physicians and giving them shortcuts and diagnostic absolutes.

As discussed already, every test has a finite error rate at the level of performance (that we try to manage with QA procedures) and also has some reported association to the disease state – positive and negative predictive values.  The predictive power is derived from the sensitivity and specificity of the test in one or more populations.  (and it changes depending on the prevalence of disease in the population).  Bottom line – no test is perfect and every test results should be considered carefully in light of the situation and reliability of the test itself.  Some (actually most) tests cannot be used to “rule out” a diagnosis because few have perfect sensitivity.

I frequently hear patients and family members (and have been told myself) that because test A is negative – you do not have disease X.  If test A is positive in 70% of subject with disease X, a negative test is really not helpful for an individual patient.  The correct message is that we cannot be sure about whether the patient has Disease X based on that test – we only know that the test is negative and 30% of patients who truly had Disease X had a negative test.
It is really a problem for diagnostic error to not take those basic epidemiology facts into account when assessing test results.  In the NY Times article the consequences were wrongful imprisonment and major losses of life stability.  In our patients it may mean that they are sent out of the ER – told that they didn’t have a heart attack/strept infection/fracture – and may have a bad outcome, because the judgement was made on the negative test result – not the whole picture.  The doctor who doesn’t see the potential for a test to be wrong – doesn’t hedge his/her discussion with the patient and emphasize the need to watch for symptoms and return.

I would argue that there is far too much reliance on test results as an absolute.  I think it is done in part because providers don’t understand the science of testing and partly to fit into algorithms.  I also think that just like for the police – it meets a need.   That need is to move patients through the system at the cost of diagnostic accuracy.

Liz

From: HM Epstein <hmepstein at GMAIL.COM>
Reply-To: "IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG" <IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG>, HM Epstein <hmepstein at GMAIL.COM>
Date: Tuesday, July 12, 2016 at 1:53 PM
To: "IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG" <IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG>
Subject: Re: [IMPROVEDX] Diagnosis gone awry: A flawed drug test could be sending thousands of innocent people to jail each year

Thanks for sharing that, Mark.

This is a hot button for me, since before I focused on diagnostic error, I wrote about the issues and risks families face when children are accused of breaking alcohol consumption laws.

These often faulty field tests go hand in glove with the tests done on potentially impaired drivers which don't test for current intoxication but test instead for signs of drug use that could be as old as two weeks or more. The statistics around alcohol and drug use and driving are often based on outmoded and coerced urine and blood tests.

Once in the system, the arrested person rarely has access to knowledgeable counsel, just like the woman in the article. Pro-publica also did an exhaustive investigative review of how often people are arrested and falsely accused who then lose their automobiles - even if they are found not guilty - which are sold by the arresting police precinct or its municipality. Those proceeds go for new gear for the precinct or for overtime pay so the police officers can then stop more drivers and accuse them of driving under the influence. There's a lot more but it is off topic for this thread.

Best,
Helene


--

hmepstein.com<http://hmepstein.com>
@hmepstein
Mobile: 914-522-2116

Sent from my iPhone





On Jul 12, 2016, at 2:09 PM, Mark Graber <graber.mark at GMAIL.COM<mailto:graber.mark at gmail.com>> wrote:
This is a disturbing article in this week’s NY Times magazine on the roadside tests police use to detect narcotics.  People are being jailed for narcotics possession based on tests that have high, and unknown, rates of false positive results.

http://tinyurl.com/zhqm44o

________________________________

Address messages to: IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG<mailto:IMPROVEDX at list.improvediagnosis.org>

To unsubscribe from IMPROVEDX: click the following link:
http://list.improvediagnosis.org/scripts/wa-IMPDIAG.exe?SUBED1=IMPROVEDX&A=1
or send email to: IMPROVEDX-SIGNOFF-REQUEST at LIST.IMPROVEDIAGNOSIS.ORG<mailto:IMPROVEDX-SIGNOFF-REQUEST at list.improvediagnosis.org>

Visit the searchable archives or adjust your subscription at: http://list.improvediagnosis.org/scripts/wa-IMPDIAG.exe?INDEX

Moderator:David Meyers, Board Member, Society for Improving Diagnosis in Medicine

To learn more about SIDM visit:
http://www.improvediagnosis.org/

________________________________

Address messages to: IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG

To unsubscribe from IMPROVEDX: click the following link:
http://list.improvediagnosis.org/scripts/wa-IMPDIAG.exe?SUBED1=IMPROVEDX&A=1
or send email to: IMPROVEDX-SIGNOFF-REQUEST at LIST.IMPROVEDIAGNOSIS.ORG

Visit the searchable archives or adjust your subscription at: http://list.improvediagnosis.org/scripts/wa-IMPDIAG.exe?INDEX

Moderator:David Meyers, Board Member, Society for Improving Diagnosis in Medicine

To learn more about SIDM visit:
http://www.improvediagnosis.org/

NOTICE: This email message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message.

To unsubscribe from the IMPROVEDX:
mail to:IMPROVEDX-SIGNOFF-REQUEST at LIST.IMPROVEDIAGNOSIS.ORG
or click the following link: IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG

Address messages to: IMPROVEDX at LIST.IMPROVEDIAGNOSIS.ORG

For additional information and subscription commands, visit:
http://www.lsoft.com/resources/faq.asp#4A

http://LIST.IMPROVEDIAGNOSIS.ORG/ (with your password)

Visit the searchable archives or adjust your subscription at:
http://list.improvediagnosis.org/scripts/wa-IMPDIAG.exe?INDEX

Moderator: David Meyers, Board Member, Society to Improve Diagnosis in Medicine

To unsubscribe from the IMPROVEDX list, click the following link:<br>
<a href="http://list.improvediagnosis.org/scripts/wa-IMPDIAG.exe?SUBED1=IMPROVEDX&A=1" target="_blank">http://list.improvediagnosis.org/scripts/wa-IMPDIAG.exe?SUBED1=IMPROVEDX&A=1</a>
</p>

HTML Version:
URL: <../attachments/20160712/7ceeb6e1/attachment.html>


More information about the Test mailing list