The Basis of the Claim

The scientific basis for the assertion regarding medical errors stems from a 2016 commentary published in the prestigious British Medical Journal (BMJ). In this article, the authors synthesized findings from several studies examining deaths potentially linked to medical mistakes, calculated an average rate from these studies, and applied it to hospitalization data in the U.S.

With approximately 35 million hospitalizations recorded in the U.S. in 2013, and a reported rate of 71 fatalities per 10,000 hospital stays due to medical errors, the researchers estimated around 250,000 deaths annually. This statistic positioned medical errors as the third leading cause of death in the country, following heart disease and cancer.

This estimation is understandably concerning. If one accepts these figures, it suggests that individuals are more likely to die due to a negligent healthcare provider than from gun violence or traffic accidents—an unsettling thought.

Fortunately, the actual number is likely much lower. Let's explore why.

Identifying the Flaws

The first significant issue with the BMJ study is that many of the statistics derived from the four studies cited are inaccurate. This is concerning, as these figures form the foundation of the entire claim.

For instance, the BMJ authors reference a 2004 study, asserting that there were 389,576 deaths attributed to “preventable events.” However, this figure is not found in the original paper, which cites over 100,000 fewer deaths:

> “Of the total of 323,993 deaths among patients who experienced one or more PSIs from 2000 through 2002, 263,864, or 81%, of these deaths were potentially attributable to the patient safety incident(s).”

A glance at the BMJ's results table reveals many inconsistencies. For example, the Classens et al. study mentions eight deaths linked to medical errors, yet the BMJ table records nine. Similarly, the Landrigan et al. article states that “Of the identified preventable harms…9 caused or contributed to a patient’s death (category I),” while the BMJ lists fourteen.

Thus, the inaccuracies in the figures are a troubling sign. Beyond erroneous numbers, there are additional flaws in the “third leading cause” claim. The BMJ authors extrapolated the findings from these studies to apply to every hospitalization in the U.S.—a move that is utterly unfounded.

The studies referenced cover populations that are not reflective of the U.S. demographic. For example:

1. A review of Medicare patients from 2000–2002
2. A smaller examination of Medicare patients
3. A study involving adults in three unnamed large hospitals
4. An analysis of adults from ten hospitals in North Carolina

None of these samples accurately represent the general U.S. population. Medicare recipients are, by definition, older and/or disabled, while a small sample from one state cannot be generalized to the entire country. Furthermore, the BMJ authors multiplied the death rate by the total number of hospitalizations in the U.S., which includes children, while the studies were conducted solely on adults.

In summary, this extrapolation is fundamentally flawed. It is illogical to draw conclusions about the entire U.S. population based on these biased samples.

Additional Concerns

The most significant issue, arguably, revolves around the definition of a death attributed to medical error.

Certain situations are clear-cut where medical errors lead to death—such as missed diagnoses due to incorrect test results or surgical mishaps. The BMJ article itself suggests these obvious cases:

> “We have estimated that medical error is the third biggest cause of death in the US and therefore requires greater attention. Medical error leading to patient death is under-recognized” (BMJ, 2016).

These statements imply that the deaths discussed are directly due to medical errors. However, the studies cited do not support this assertion. Instead, the authors of the four studies used retrospective evaluation tools on patient records to determine if a medical error may have contributed to a death.

For example, the large Medicare study from 2004 found that many medical issues stemmed from what is known as “Failure to Rescue.” This term refers to the healthcare system's inability to adequately respond to complications during treatment, which could involve anything from incorrect antibiotic dosing to neglecting to order necessary tests. The authors utilized software to identify potential medical issues based on routine codes associated with errors.

This method is subjective and primarily assessed after the fact—it is easier to suggest that a different medication might have improved outcomes based on a review of records, but determining whether this constitutes a medical error is complicated and not straightforward, contrary to the BMJ paper's implications.

Moreover, none of the studies explicitly claimed that medical errors caused the deaths they reviewed. Instead, the studies used phrases like “potentially contributed to” or “may have impacted,” as they did not assess causality directly—they merely noted instances of medical errors alongside patient deaths without definitively linking the two.

This approach has artificially inflated the estimates of deaths directly caused by medical errors to unreasonable levels. The BMJ's claim that medical errors are the “third leading cause” implies that roughly one-third to half of all hospital deaths result directly from medical mistakes. Yes, you read that correctly—30–50% of all hospital deaths would need to be due to medical errors for this claim to hold true.

However, this notion is contradicted by higher-quality evidence. A thorough British review of randomly selected patients found that only 3.6% of hospital deaths were likely linked to preventable medical issues. This study carefully examined each record to determine whether a medical error occurred and if it contributed to the patient's death.

In essence, based on objective evaluations by trained clinicians, the death rate attributable to medical errors is likely at least ten times lower than the estimates from the 2016 BMJ article. This would equate to around 20,000 to 30,000 deaths in the U.S. due to potentially avoidable medical issues, placing it around the 16th to 20th leading cause of death depending on the year.

This brings us back to the original point—though this number is significant, it is debatable whether all these deaths are indeed preventable. The British review suggested that more clarity surrounding “do not resuscitate” orders could have decreased these figures.

Nonetheless, the assertion that medical errors rank among the top causes of death in the U.S. and beyond is simply incorrect. While medical errors remain a significant issue that necessitates continued attention and improvement, they are not the third leading cause of death in America.