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Colorectal cancer, lung cancer and breast cancer are the three most frequently missed diagnoses in outpatient clinics and academic medical centers, a recent study published in JAMA Network Open found. Heart attack and prostate cancer round out the top five.
Combing through data from patient safety incident reports, malpractice claims, morbidity and mortality rounds (conferences that review patient deaths and complications), and focus group responses, researchers found 836 relevant diagnostic errors, which they used to identify the 10 most common missed or delayed diagnoses and explore what went wrong in the process. The findings highlight what experts say is a key safety issue in modern medical care.

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“Missed diagnoses are common, and they’re often overlooked,” says study coauthor Gordon Schiff, M.D., associate director of Brigham and Women’s Center for Patient Safety Research and Practice and an associate professor of medicine at Harvard Medical School in Boston.
In fact, research shows that some 12 million American adults are misdiagnosed annually in outpatient settings. That’s about 5 percent of patients, though some experts say the percentage is likely higher. And it’s estimated that 40,000 to 80,000 people die each year from diagnostic failures in U.S. hospitals. What’s more, a report from the National Academies of Sciences, Engineering, and Medicine states that most people will experience a missed or delayed diagnosis in their lifetime, sometimes with devastating consequences.
10 Most Commonly Missed or Delayed Diagnoses by Medical Condition
Derived from 836 relevant cases from patient safety incident reports, malpractice claims, morbidity and mortality rounds (conferences that review patient deaths and complications), and focus group responses. Reported in JAMA Network Open.
- Colorectal cancer
- Lung cancer
- Breast cancer
- Myocardial infarction (heart attack)
- Prostate cancer
- Stroke
- Sepsis
- Bladder cancer
- Pulmonary embolism
- Brain hemorrhage
Previous research supports the findings of this latest report. Nevertheless, a few other conditions can be added: Pneumonia, heart failure, kidney failure and urinary tract infections are among those often missed in the primary care setting, a study published in JAMA Internal Medicine found. Fractures, abscesses and aortic aneurysms are also commonly missed, according to another report published in the same journal.
Why do diagnostic errors occur?
Reasons for diagnostic errors run the gamut. Sometimes it’s miscommunication between patient and doctor: The patient may fail to describe their symptoms accurately, or the doctor misses something important in the patient’s story. Other times an incorrect test is ordered, or a test is read incorrectly. Data in electronic medical records can be disorganized, and sometimes referrals aren’t followed up on.
“It could be so many of those reasons,” even multiple reasons, says Hardeep Singh, M.D., a professor of medicine at Baylor College of Medicine and chief of Health Policy, Quality and Informatics (HPQI) at the Michael E. DeBakey VA Medical Center in Houston.