Where is Medical Malpractice Most Prevalent & “The Big Three”

In 2020, Covid-19 was the third leading cause of death in the United States, as we faced global pandemic. However, prior to the events of 2020, a 2016 study from Johns Hopkins suggested that nearly one-third of all deaths were actually caused by medical malpractice. Regardless of medical malpractices’ position, it remains one of the most threatening realities citizens in the U.S. face, and its impacts on the nation are staggering. 

Medical malpractice claims are largely concentrated around diagnostic and prescription errors. Diagnostic errors center on three diseases, specifically, referred to as the “Big Three,” and includes errors in treating infections, vascular events, and cancers. Together these two types of errors represent a vast majority of malpractice cases and claim over an estimated 200,000 lives annually.  

Vigilance in choosing a physician, and being aware of weaknesses in the healthcare system, such as understanding where most medical malpractice errors occur, can help patients make informed decisions about their care. 

What are the Most Common Medical Malpractice Errors?

There have certainly been some very strange medical malpractice claims over the years, from the amputation of the wrong limb, to leaving surgical instruments inside of patients. As rare as these types of claims are, there are a few that happen on a regular basis that can still be very dangerous, and in some cases, even fatal. 

Though the one-off, strange malpractice cases do garner the most attention, it is the regular, recurrent errors that cause the most harm to patients. A missed, or delayed diagnosis permanently disables or kills an estimated 100,000 patients in the United States each year, making misdiagnosis one of the most common, costly, and deadly medical malpractice errors. These types of errors are only rivaled by prescription errors, which claim an estimated 98,000-128,000 lives annually. 

Diagnostic errors result in missed or delayed diagnosis and is an umbrella term that can relate to mismanagement of any and all illnesses and injuries. Medication, or prescription, errors come in many forms: patients can be given the wrong prescription, a patient can have an allergic reaction to a particular drug or have a condition that can be worsened by a medication, or different medications may interact with each other to trigger a serious or harmful reaction known as a drug interaction

Misdiagnosis or Delayed Diagnosis

Even before the 2020 Johns Hopkins study was released, diagnostic errors were already making waves in the medical community. Between 2006 and 2015, researchers evaluated 11,592 diagnostic error cases from a list of medical malpractice claims compiled in the National Comparative Benchmarking System database.

A diagnostic error is defined by The National Academies of Sciences, Engineering, and Medicine as the failure to establish an accurate and timely explanation of the patient’s health problem and/or communicate that explanation clearly to the patient.

Simply put, these are diagnoses that are delayed, wrong, or missed altogether.

Diagnostic errors certainly occur across all healthcare departments, but the most serious errors are connected with cancer. In fact, nearly three-fourths of all serious errors are affiliated with cancer, which comprise 37 percent of all diagnostic errors. The next highest volume error deals with vascular events and comprises 22 percent of all diagnostic errors. Lastly, infections make up a total of 13 percent of all diagnostic errors. These three errors are collectively known as “The Big Three”.

Prescription Drug Errors

A close contender when it comes to the most common medical malpractice claims are prescription drug, or medication errors. Medication errors are far from new, but with more than 12 million chemical substances now available, taking physician prescribed medication continues to become an increasingly dangerous undertaking—often worthwhile, understanding the risks is the first step in avoiding catastrophe. 

In 1999, a report called To Err Is Human by the Institute of Medicine of the National Academy of Sciences, estimated that as many as 98,000 hospital patients die every year as a result of preventable errors, including medication mistakes. A more recent, 2016 article analysis estimates 128,000 Americans die each year as a result of taking medications as prescribedor nearly five times the number of people killed by overdosing on prescription painkillers and heroin combined.

These errors are costly―in dollars―but more importantly, in lives lost. Prescription errors are the second most frequent, and expensive, error due to medical malpractice claims, which cost more than $219 million a year, according to the Physicians Insurance Association of America.

A Closer Look at “The Big Three” of Diagnostic Errors

Deemed “The Big Three” by researchers at Johns Hopkins, these types of health conditions account for about 75 percent of misdiagnoses-related harms, according to a new study done in May of 2020. The big three are diagnostic errors in treating cancer, infection and vascular events. 


The human body has many organisms living within it, usually with no negative repercussions. But organisms such as bacteria, viruses, fungi or parasites, under certain circumstances, can cause harm to the body in the form of an infection.

There are infections that can be passed to humans through contact with insects or animals, some are transmitted through consuming contaminated food or water. Many infectious diseases are passed from person to person. 

The symptoms each organism causes in the body differs greatly, but, two of the most commonly seen symptoms of infection are fever and fatigue. Mild infections often require nothing more than rest and home care, but severe infections may result in hospitalization.

Vascular Events/Disease

Vascular disease is any condition that affects the network of blood vessels in the human body. This network is known as the vascular or circulatory system. 

Within this network, the vessels are responsible for moving blood throughout the body. In the center of this system is the heart which pumps oxygen and nutrients to feed tissue and carry off waste. Arteries move blood away from the heart, veins return it.

Lymph vessels and lymph nodes are part of a separate cleaning system that rids the body of damaged cells. They also help protect the body from infections and cancer. The vessels pick up fluid from tissues throughout the body. That fluid drains back into veins under the collarbones.

Vascular diseases range from problems with arteries, veins, and vessels that carry lymph to disorders that affect how the blood flows. A disease can mean bodily tissues aren’t getting enough blood, a condition called ischemia, as well as other serious, even life-threatening, problems.


Cancer is a disease that occurs when cells in the human body begin to divide uncontrollably. The cells can then begin to spread into other areas of the body.  

The human body is made up of trillions of cells, which means cancer can start in almost any part of the body. When the body is functioning properly, cells grow old and die off and new ones take their place, this is the normal process of healthy cells. 

When cancer develops, this orderly process breaks down. As cancer cells become more abnormal, old or damaged cells survive when they should die, and new cells form when they are not needed. These extra cells can divide unimpeded and may form growths called tumors.

Many cancers form solid tumors, which are masses of tissue. Cancers of the blood, such as leukemias, generally do not form solid tumors.

Cancerous tumors are malignant, when they begin to spread into, or invade, nearby tissues. In addition, as these tumors grow, some cancer cells can break off and travel to distant places in the body through the blood or the lymphatic system and form new tumors far from the original growth.

Unlike malignant tumors, benign tumors do not spread into, or invade, nearby tissues. Benign tumors can sometimes be quite large, however. When removed, they usually don’t grow back, whereas malignant tumors sometimes do. Unlike most benign tumors elsewhere in the body, benign brain tumors can still be life threatening.

Specific Diseases Caused by the “Big Three”

Of the total number of patients found to have been negatively affected by diagnostic errors, 34 percent suffered permanent disability or death. As each of these outcomes originated from a delayed or missed diagnosis, diagnostic errors are now the leading cause of serious harm among medical errors.

Continuing to drill down into the specifics of what illnesses or injuries are at the root of the diagnostic error mystery. Within those three areas, the researchers identified 15 more specific conditions that, combined, account for nearly half of all the serious, misdiagnosis-related harms.

The primary disease in each category is stroke, sepsis, and lung cancer, respectively. Other most-commonly misdiagnosed conditions include heart attack, venous thromboembolism, aortic aneurysm and dissection, arterial thromboembolism, meningitis and encephalitis, spinal infection, pneumonia, endocarditis, alongside breast, colorectal, prostate, and skin cancers.

Malpractice Related Deaths Take a Back Seat to Covid-19

It remains to be seen, if after the Covid-19 pandemic, malpractice will regain its place as the third leading cause of death in the United States. The more patients can do to educate themselves on when and how malpractice occurs, the safer and the more likely to have positive medical outcomes they will be.

While prescription and diagnostic errors make up the bulk of medical malpractice cases, there are underlying diseases and practices that ultimately drive the numbers, earning these two categories of errors their place at the top of the malpractice list for most common cases. But at the end of the day, no matter how specific or obscured, diagnostic and prescription drug errors cause great harm to patients. 

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