Dangers of a Misdiagnosis

The Serious Impact of Misdiagnosis

The Society to Improve Diagnostics in Medicine (SIDM) say that at least one in ten patients with a serious medical condition are initially misdiagnosed. Three quarters of misdiagnosed cases occur in these three categories of medical conditions:

  • Cancer
  • Vascular events
  • Infection

The Society have formed a collaboration of over fifty healthcare groups with the single objective of eliminating diagnostic error, which they say is the most important safety issue in medicine today, causing the most patient harm.

In a news item, SIDM report that, "Every nine minutes, someone in a US hospital dies due to a medical diagnosis that was wrong or delayed". CEO and co-founder of SIDM, Paul Epner says, 

Nearly everyone will receive an inaccurate diagnosis at some point in their life and for some, the consequences will be grave. Major improvement is needed to systematically identify how to improve diagnostic quality and reduce harm to patients.

The American clinical laboratory magazine, Dark Daily go further to suggest that not only should misdiagnosis be included as a fundamental 'Sentinel event', but it should be at the top of the Sentinel event list.

Research for a study carried out by a team from the Johns Hopkins University School of Medicine and funded by the SIDM reported in the journal Diagnosis, showed that one in three malpractice cases that resulted in death or serious harm to patients are due to misdiagnosis. After analysing more than 55,000 malpractice claims, the researchers found that 34% of those cases which resulted in death or permanent disability could be attributed to misdiagnosis.

Misdiagnosis Affects at least One in Ten Patients

SIDM say that diagnostic errors affect an estimated 12 million patients in the US each year, and that approximately one in ten patients with a serious medical condition are initially misdiagnosed. In addition, an estimated 40,000 to 80,000 people die each year from diagnostic errors in US hospitals, and it is probable that at least that many patients suffer from permanent disability annually due to improper diagnosis. SIDM also say that it is likely that diagnostic errors cause more harm to patients than all other medical errors combined and are responsible for an increasing number of malpractice cases.

Anyone who is concerned about their diagnosis should seek a second opinion and prepare for their next consultation using the Consultation Checklist.


The process of determining which condition a patient may have. Full medical glossary
An abbreviation for diabetes mellitus. Full medical glossary
An abbreviation for epididymo-orchitis. Full medical glossary

Diagnoses that are missed altogether, wrong, or should have been made much earlier

Full medical glossary

Sentinel events are defined by the The Joint Commission (TJC) in the USA as, "any unanticipated event in a healthcare setting resulting in death or serious physical or psychological injury to a patient or patients, not related to the natural course of the patient's illness. Sentinel events specifically include loss of a limb or gross motor function, and any event for which a recurrence would carry a risk of a serious adverse outcome."

These events include, "unexpected occurrences involving death or serious physical or psychological injury, or the risk thereof" and all of the following, even if the outcome was not death or major permanent loss of function:

  • Infant abduction, or discharge to the wrong family.
  • Unexpected death of a full-term infant.
  • Severe neonatal jaundice (bilirubin over 30 milligrams/deciliter).
  • Surgery on the wrong individual or wrong body part.
  • Instrument or object left in a patient after surgery or another procedure.
  • Rape in an acute-care setting.
  • Suicide in an acute-care setting, or within 72 hours of discharge.
  • Haemolytic transfusion reaction due to blood group incompatibilities.[1]
  • Radiation therapy to the wrong body region or 25% above the planned dose.

The clinical laboratory organisation, Dark Daily suggest that this list should also include 'misdiagnosis' and other preventable diagnostic errors.

Full medical glossary