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You Have Likely Been the Victim of Diagnostic Mistakes

Diagnostic mistakes are common, often leading to permanent disability and death. A study says nearly 1 out of 5 patients are misdiagnosed.

Some mistakes are worse than others. When Alaska Airlines Flight 1282 had a mid-cabin door plug blow out shortly after takeoff on January 5, 2024, there were a lot of unhappy passengers. The flight was terrifying and the plane had to make an emergency landing. It seems someone may have failed to install the bolts that should have held the plug in place. Or, if they were installed, they might have been loose. All Boeing 737 Max 9s with a plug door were grounded until the authorities can figure out what went wrong and how to fix it. Fortunately, no one died. We only wish that the medical profession would be as vigilant as the FAA. A new report (JAMA Internal Medicine, Jan. 9, 2024) suggests that diagnostic mistakes are far more common than anyone ever imagined. The resulting deaths are a national scandal that regulators have ignored for decades.

The Disgrace of Diagnostic Mistakes:

We have been writing about medical mistakes for decades. No one seems to care, including physicians. If they do care, they have done very little to fix the problem. The latest research involves 2,428 patient records from 29 hospitals. Highly trained physicians reviewed the medical records of patients who died or who were transferred to an intensive care unit (ICU) between January 1 and December 31, 2019. The analysis of their records revealed that 23% of the initial diagnoses were delayed or mistaken. These errors harmed or contributed to the deaths of 18% of the patients in the study.

What are “diagnostic errors”? According to the researchers they are:

“the failure to (a) establish an accurate and timely explanation of the patient’s health problem(s) or (b) communicate that explanation to the patient.”

The authors conclude:

“In this multicenter study of a selected group of medical patients who died in hospital or who were transferred to an ICU, diagnostic errors were common and associated with patient harm.”

How Common Are Diagnostic Errors?

The researchers writing in JAMA Internal Medicine, Jan. 8, 2024 note that:

“Meta-analyses of studies reporting diagnostic errors determined via a range of methods suggested rates of 10% or lower, while autopsy studies have described rates between 5% and 25%. Finally, recent work calculated a national prevalence closer to 20% using a combination of administrative data and literature-based rates. Our results fall in the upper end of the range…”

Please try to process that stunning revelation. These highly regarded medical researchers are suggesting that nearly 1 out of 5 patients experiences a misdiagnosis. We find that mind boggling.

Why Doesn’t Anyone Care?

On January 11, 2024 the FAA (Federal Aviation Administration) updated its investigation into the “Grounding of Boeing 737 MAX 9 Aircraft.” This federal agency stated in no uncertain terms:

“This incident should have never happened and it cannot happen again.”

Remember, no one died! As far as we can tell, no one was seriously injured. Nevertheless, the FAA is conducting an investigation to make sure it never happens again! The FAA states:

“Every Boeing 737-9 Max with a plug door will remain grounded until the FAA finds each can safely return to operation.”

When a diagnostic error leads to a patient’s death, no one seems to notice. The family may not even be told that there was a mistake. The white curtain of silence keeps a lot of healthcare harm secret. Diagnostic errors are not mentioned on most death certificates. “Cause of death” is rarely, if ever, attributed to a medical mistake.

Even when there is awareness, there is no federal agency to investigate or “ground” the doctor, clinic or hospital where the error occurred. Medical societies are not very good at managing medical mistakes. And no one has come up with a good system for detecting or correcting this massive problem.

How Many Diagnostic Mistakes Do Doctors Make Each Year?

David Newman-Toker, MD, PhD, is Professor of Neurology, Ophthalmology, and Otolaryngology at Johns Hopkins School of Medicine. He is Director of the Armstrong Institute Center for Diagnostic Excellence. Dr. Newman-Toker has been studying errors in diagnosis for many years. He and his colleagues published a shocking study in the journal BMJ Quality & Safety (July 17, 2023).

These researchers analyzed data from more than 20 million hospital records. They calculate that 795,000 patients are harmed by misdiagnosis each year. That includes 371,000 deaths and 424,000 permanent disabilities.

And that may be conservative. The worst case scenario, according to these investigators, was 1,023,000 “serious harms annually” in the US. Overall, they report that doctors make an incorrect diagnosis 11% of the time. In other words, one out of every 10 patients is not diagnosed correctly.

The latest research published in JAMA Internal Medicine, Jan. 8, 2024, suggests that may be far too conservative. The actual number may be closer to 20% or one out of every five patients.

How can I put that into context for you? Imagine if, when you take your car to the repair shop, the mechanic made a serious mistake 1 out of 5 times. Just think what would happen if the pilot of your airplane landed at the wrong city 1 out of every 5 flights. What if you receive the wrong amount to your bank account 1 out of every 5 deposits? You would doubtless be furious in all these scenarios.

And yet far more important mistakes occur when you are seen by health care professionals. Permanent disability or death are irreversible mistakes!

Be Especially Concerned About These Conditions:

The top five conditions that are misdiagnosed are stroke, sepsis, pneumonia, blood clots in the legs or lungs, and lung cancer.

The researchers point out that there is variability depending upon the situation:

“Disease distributions for serious misdiagnosis-related harms differ across clinical settings and age groups. Missed vascular events and infections dominate in hospitals and emergency departments, while missed cancers likely dominate in primary care. In adult care, vascular events are typical, while in paediatric care, infections are typical. Thus, diseases that should be the focus of interventions to improve diagnostic performance would ideally be tailored to the specific clinical context.”

Dr. Newman-Toker told USA Today (July 18, 2023):

“The enormous numbers of misdiagnoses are a public health emergency, the report’s lead author said. ‘Diagnostic errors are, by a wide margin, the most under-resourced public health crisis we face,’ said Dr. David Newman-Toker, director of the Johns Hopkins diagnostic excellence center.

“Medical professionals almost always misdiagnose diseases when a person’s symptoms look like possible symptoms for a different condition, Newman-Toker told USA TODAY. The more subtle the symptom appears, the more likely it is the patient’s problem will be misdiagnosed, he said.

“‘We don’t miss strokes when somebody is paralyzed on one side and can’t talk,’ he said. ‘We miss them when they look like something else that’s benign.'”

Why Don’t Medical Authorities Acknowledge Diagnostic Mistakes and Do Something About Them?

We have been writing about diagnostic mistakes and medical errors for a very long time. Our book,  Top Screwups Doctors Make and How To Avoid Them was entirely ignored by most health professionals. We received zero requests for talks at medical schools, schools of pharmacy or nursing schools. The book virtually disappeared without a trace, though you can find it at this link.

We do not understand why medical errors are not listed among the top killers by the CDC. Instead, you will find

  • Heart disease: 695,547
  • Cancer: 605,213
  • COVID-19: 416,893
  • Accidents: 224,935
  • Stroke: 162,890

It is entirely possible that many of those stroke patients could have survived if they had been diagnosed correctly in a timely manner. Perhaps fewer people would have died of cancer if their condition had been accurately identified early on.

Not The First Time Research Points to Diagnostic Mistakes as a Horrific Problem:

Research published by the Agency for Healthcare Research and Quality (Dec. 15, 2022) should have shaken the pillars of modern medicine.

The stats are nothing short of shocking:

“We estimate that among 130 million emergency department (ED) visits per year in the United States that 7.4 million (5.7%) patients are misdiagnosed, 2.6 million (2.0%) suffer an adverse event as a result, and about 370,000 (0.3%) suffer serious harms from diagnostic error. Put in terms of an average ED with 25,000 visits annually and average diagnostic performance, each year this would be over 1,400 diagnostic errors, 500 diagnostic adverse events, and 75 serious harms, including 50 deaths per ED.”

Perhaps your eyes glaze over with so many numbers. But please reflect for a moment that there are 7.4 million patients who are misdiagnosed every year in emergency rooms in the U.S. If someone is misdiagnosed, she is likely to get the wrong treatment.

The report suggests that these misdiagnoses lead to:

“… 371,000 (PR 142,000 to 909,000) serious misdiagnosis-related harms, including more than 100,000 permanent, high-severity disabilities and 250,000 deaths.”

Disability and Death:

You just read that 350,000 people experience disability and/or death each year as a result of a misdiagnosis in an emergency room. And yet we predict that this statistic will disappear without a trace.

Hospitals, emergency departments, medical schools and insurance companies will ignore these startling statistics. Nothing will change!

The Other Side of the Coin:

A study in JAMA Internal Medicine (April 5, 2021) reported that health practitioners dramatically overdiagnose diseases. That can lead to overtreatment. And that, in turn, can lead to side effects or other complications.

Pilots Gone Astray:

Here’s an example of an unforgiving public when professionals make mistakes. On October 21, 2009, Northwest Airlines Flight 188 left San Diego for Minneapolis. For reasons that still remain somewhat mysterious the pilots overflew the airport by 150 miles. They landed in Minneapolis more than an hour late.

No one was injured and no one died because of this error. The pilots were humiliated in the media. The FAA revoked their pilot certificates and the National Transportation Safety Board instituted significant changes in procedures as a result of this screwup.

Would You Fly if 1 out of 5 Flights Had An Error?

Imagine for a moment that there was an airplane crash once a month. Would you be uncomfortable flying? What if I told you that the number of diagnostic errors leading to deaths was equivalent to a jet crashing every day…day in and day out. Would you get on an airplane if you knew that there was a significant possibility it would crash?

Every day there are substantial numbers of diagnostic errors. A shocking number result in disability or death. And yet there are no headlines, no regulatory actions and no meaningful efforts to prevent more.

When Health Professionals Make Diagnostic Mistakes:

If physicians, nurse practitioners or physician assistants make errors, they can easily go undetected. Health professionals rarely get called out for diagnostic mistakes. Patients may not even realize something has gone wrong until it’s too late.

Researchers evaluating primary care visits estimate that about 5% of diagnoses in that setting are in error, affecting approximately 12 million adults each year (BMJ Quality and Safety, Sep. 2014). Please note that theses are “normal” visits to health care professionals, not trips to the ER! Yet the error rate is quite similar.

The researchers conclude:

“Based upon previous work, we estimate that about half of these errors could potentially be harmful.”

If you think 12 million is a large number, consider that this does not include diagnostic mistakes made in hospitals, specialty clinics or nursing homes. If people were actually counting errors, it is likely the number would be far greater.

Do Doctors Mess Up Diagnosis?

How good are physicians, nurse practitioners and physician assistants when it comes to diagnosis? The study in JAMA Internal Medicine (April 5, 2021) suggests that many health care providers drastically overestimate the likelihood of a specific disease condition. The investigators surveyed 553 health professionals. They tested them on four different hypothetical scenarios: patients presenting with possible symptoms of heart disease, breast cancer, pneumonia and urinary tract infections.

For each scenario, the researchers had calculated probabilities based on the scientific literature. The subjects were asked about the likelihood of these conditions before seeing test results and again after they were provided.

In both situations, the:

“practitioners consistently overestimated both pretest and posttest probabilities, often dramatically.”

The authors conclude:

“Widespread overestimates of the probability of disease likely contribute to overdiagnosis and overuse.”

How far off were these health practitioners? Way off! Remember, even after getting test results from chest X-rays, mammograms, exercise stress tests and urine cultures, mistakes were made.

The authors report:

“In this survey study, in scenarios commonly encountered in primary care practice, practitioners overestimated the probability of disease by 2 to 10 times compared with the scientific evidence, both before and after testing.”

A ten fold error is huge.

Malpractice Claims and Diagnostic Mistakes:

Depending upon which study you read, you get either a depressing view or a horrifying view of health care harm. Research on settled malpractice claims concluded that 80,000 to 160,000 people suffer serious disability or death due to misdiagnosis each year (Diagnosis, Sept. 2019). About three-fourths of these grave mistakes involve one of the “big three:” cardiovascular conditions, infections or cancer.

These authors note in their discussion that no one really knows how many people are being harmed or killed by serious diagnostic mistakes in primary care settings.

Citing the 2014 BMJ Quality and Safety study, they state that it:

“…would translate to at least 4 million seriously harmed, including at least 1.7 million who died from diagnostic error.”

We grant you that that is the theoretical upper limit. The range for “serious misdiagnosis-related harms” is between 80,000 and 4 million. The reason the numbers are so varied is that no one is actually counting. The CDC does not include diagnostic mistakes on its list of leading causes of death. Death certificates rarely, if ever, list cause of death as “diagnostic error” or “medical mistake.”

Misleading Death Certificates:

What you are likely to see on a death certificate is “cardiac arrest,” “respiratory arrest” due to COVID-19 or “intracerebral hemorrhage” (stroke). When Helen Graedon (my mother) died after a series of medical errors, the death certificate stated that her death was caused by “cardiac arrest” due to “hypotension” (low blood pressure) as a consequence of “retroperitoneal hemorrhage” (internal bleeding). Nowhere was it mentioned that the medications she was mistakenly given in the hospital triggered something called serotonin syndrome that likely contributed to the internal bleeding.

If anyone were counting, diagnostic mistakes would be a leading cause of death in America. But unlike heart disease and cancer, there is no Institute of Diagnostic Mistakes. Politicians allocate billions of taxpayer funds to the National Cancer Institute, the National Heart, Lung, and Blood Institute, the National Institute on Alcohol Abuse and Alcoholism and the National Institute of Allergy and Infectious Diseases. But barely a drop in the bucket goes to preventing healthcare harm due to faulty diagnosis.

Why Proper Diagnosis Matters!

When you see doctors for troublesome problems, you probably expect them to uncover the reasons for your symptoms. Accuracy matters, because undergoing treatment for the wrong condition won’t help and may do you harm.

Treatment delay could be deadly. In addition, you could be taking medicine with potentially serious side effects that won’t help your condition at all.

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Overlooking Drug-Induced Side Effects:

Doctors may also have trouble diagnosing reactions to medications they have prescribed. We have heard from hundreds of people describing a wracking cough that took them into the clinic time after time.

Some took cough medicine or antibiotics that did nothing, while others underwent multiple tests for infection, allergy or asthma, without result. Eventually, for these readers, the source of the problem was identified as an ACE inhibitor blood pressure medicine, usually lisinopril.

While the ACE-inhibitor cough is extremely uncomfortable, it is rarely life threatening. A different reaction to this drug, angioedema, can block airways. Intestinal angioedema can also cause serious harm, but it may be difficult to diagnose.

One reader related this experience:

“I came across your website while literally writhing in agony after my first dose of lisinopril. My stomach felt like I had eaten a bag of glass. After hours of agony and consulting Dr. Google, I knew what it was and went to the ER.

“None of the doctors had even heard of it before. I kept yelling to my husband, ‘Tell them about intestinal angioedema!’ All three doctors were flabbergasted that just one dose could cause this. I was in the hospital for four days. Moral of the story–be your own advocate!”

Millions of people take lisinopril without problems. When people do develop adverse reactions, though, health care providers must be alert to that possibility.

Protecting Yourself from Diagnostic Mistakes:

What can patients do to protect themselves from misdiagnosis? Dr. David Newman-Toker, introduced earlier, suggests that patients prepare a summary of their symptoms and history before seeing a clinician. After getting an initial diagnosis, ask:

“What is the worst thing this could be?”

Follow up with:

“Why is it not that?”

To learn more and listen to Dr. Newman-Toker describe diagnostic mistakes, you may want to listen to Show 1239: How Can We Prevent Diagnostic Disasters?

As mentioned above, we have written a book on misdiagnoses and many other medical errors. It does not spare pharmacists, who also make a shocking number of dispensing errors. The book is: Top Screwups Doctors Make and How To Avoid Them. You will find it in our bookstore at this link.

Have you ever experienced diagnostic mistakes? If so, please share your story in the comment section below.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
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  • "Diagnostic Errors in the Emergency Department: A Systematic Review" AHRQ, Dec. 2022. Comparative Effectiveness Review Number 258.
  • Newman-Toker, D., et al, "Serious misdiagnosis-related harms in malpractice claims: The “Big Three” – vascular events, infections, and cancers," Sept. 2019, https://doi.org/10.1515/dx-2019-0019
  • Singh, H, et al, "The frequency of diagnostic errors in outpatient care: estimations from three large observational studies involving US adult populations," BMJ Quality & Safety, Sept. 2014, doi: 10.1136/bmjqs-2013-002627
  • Morgan, D.J., et al, "Accuracy of Practitioner Estimates of Probability of Diagnosis Before and After Testing," JAMA Internal Medicine, April 5, 2021, doi:10.1001/jamainternmed.2021.0269
  • Manrai, A.K., "Physicians, Probabilities, and Populations—Estimating the Likelihood of Disease for Common Clinical Scenarios, JAMA Internal Medicine, April 5, 2021, doi:10.1037/h0034747
  • Newman-Toker, D.E., et al, "Burden of Serious Harms From Diagnostic Error In the USA," BMJ, July 17, 2023, http://dx.doi.org/10.1136/bmjqs-2021-014130
  • Auerbach, A.D., et al, "Diagnostic Errors in Hospitalized Adults Who Died orWere Transferred to Intensive Care," JAMA Internal Medicine, Jan. 8, 2024, doi:10.1001/jamainternmed.2023.7347
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