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You Have Likely Been the Victim of Diagnostic Mistakes

Diagnostic mistakes are common. They can lead to disability, death or unnecessary treatment. A new study reveals dramatic overdiagnosis.
You Have Likely Been the Victim of Diagnostic Mistakes
Depressed doctor leaning against wall in hospital corridor

Americans are generally unforgiving when it comes to mistakes. If a bank teller shortchanged you on a check, you would squawk, right? If the expensive fish you purchased was spoiled when you unwrapped it, you would want a replacement or your money back. Why do we accept so many diagnostic mistakes from our health professionals without a word? A study in JAMA Internal Medicine (April 5, 2021) reports that health practitioners dramatically overdiagnose diseases. That can lead to over treatment. And that 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.

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). 

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 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 “intercerebral 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.

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 is Director of the Armstrong Institute Center for Diagnostic Excellence at Johns Hopkins University School of Medicine. He 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?”

You will find 10 additional questions and ways to reduce diagnostic errors in our book, Top Screwups Doctors Make and How to Avoid Them.

In the book you will find a copy of our “Safe Patient Checklist.” We encourage you to make a copy and have your health professional fill it out at every visit. We also provide a list of the top diagnostic screwups health professionals make. More important are the Top 10 Questions to Ask to Reduce Diagnostic Disasters. The top five are:

  1. What are my primary concerns and symptoms? (This essential question will reveal if your doctor was actually paying attention). This strategy is called “teach back” and demonstrates the practitioner’s true understanding of what was related.
  2. How confident are you about this diagnosis?
  3. What further tests might be helpful to improve your confidence?
  4. Are there any findings or symptoms that don’t fit your diagnosis or contradict it?
  5. What else could it be?

Here is a link to Top Screwups. It just might save your life or the life of someone you love.

One caveat: The online shipping costs are pricey. We apologize for that. It is a function of the shopping cart and we have no control over shipping costs. There is a less expensive shipping method.

To order by mail, please send $15 plus $4 postage and handling to:

  • Graedons’ People’s Pharmacy, Dept. TSDM
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  • Durham, NC 27717-2027

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.” .
  • 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
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