Monday, February 5, 2024

795,000 Serious Diagnostic Errors


Over the last many years there has been a wide interest in medical and diagnostic error.  One can see why.  When a person is sick, or worse, when the sick one is their child or significant other,  the first thing you want is good and immediate reliable accurate and timely care.  It would be nice if that was what happened all the time.  Usually it does, sometimes it does not; sometimes it does not… but that is a topic for the next time!

The healthcare community is clearly concerned for all the right reasons to try and understand why things go amiss.   As much as there are too many events of long waits in the ER and too few family physicians, problems tend to occur infrequently, especially in countries with a well developed healthcare system.  Sometimes, probably most times when thing go badly (again, this is a rare event), it is because of person-error resulting in a missed on wrong diagnosis.

In my own studies I was able to look at provincial medical laboratory errors recorded within the healthcare system by physicians, and laboratory workers.  Because of my own knowledge and experience in laboratory quality assessment I was able to confirm the common finding that most errors in laboratory testing occur before the sample ever gets to the laboratory.  Those are really problematic because they samples get tested seemingly without difficulty or error, but the information arising can be wrong and misleading. 

The other observation, unfortunately, was that many in-laboratory errors never get reported, sometimes because people were too busy, and other times just because people chose not to report.  Some bizarrely even used the reporting process for getting others in trouble by reporting errors under another person’s name!)

This month, a group in the United States wanted to put a number on just how many errors occur that result in serious harm.  They did some looking at government and hospital records and did some interesting but definitely iffy arithmetic and came to the conclusion that some 795,000 diagnostic errors result in serious harm to patients each year.  In their paper they made two important comments, one being that in the US there are about 1 billion healthcare visits each year and the likelihood of a serious harm befalling an individual patient was about 1 in 1,000. 

They also acknowledged that their work was largely crude and a gathering of a variety of information and pointed out that much of their information is based on data that is composed of largely unverifiable estimates.  In my own mind it was much less an estimate and much more a crude  guestimate.

But all that will not matter.  Already the media has jumped to saying that people are at peril because there almost a million diagnostic errors every year in the United States.  It provides the news sharers the next new opportunity to tell everyone their very existence at jeopardy.   (For those interested, visit my blog entry on April 28, 2020… “We are all going to DIE”).

We unfortunately live in a society that is disturbingly comfortable with developing and using bad information for its own purposes.   It puts, in my opinion, an additional obligation on serious writers and investigators to ensure that their information does not get abused and misused.

In my opinion these authors have gone through an interesting exercise by, in their own words, pursuing a “novel technique” of gathering disparate information from a bunch of places, and put the information together to see if they could come up with a value that could be used as a form of marker for future study. 

By their own acknowledgement the results are an estimate.  Personally I suspect their calculation is too crude, but as they say in Australia … “Goodonya!”

There are better techniques these days for doing mass data analysis, including AI.  While the authors did not mention trying that, I would be surprised if they did not give it a shot.   

In the meantime, when you read about the near million serious errors that occur each year, before you get too healthcare phobic, put it in context.


Newman-Toker DE, Nassery N, Schaffer AC, Yu-Moe CW, Clemens GD, Wang Z, Zhu Y, Saber Tehrani AS, Fanai M, Hassoon A, Siegal D. Burden of serious harms from diagnostic error in the USA. BMJ Qual Saf. 2024 Jan 19;33(2):109-120.


Restelli V, Taylor A, Cochrane D, Noble MA. Medical laboratory associated errors: the 33-month experience of an on-line volunteer Canadian province wide error reporting system. Diagnosis (Berl). 2017 Jun 27;4(2):79-86.