Not all adverse events are preventable

Medical errors are a real problem. I won’t deny that.

It was bad enough when the often-quoted Institute of Medicine figure that 98,000 deaths per year in the US are caused by medical errors was in vogue, but now a paper in the Journal of Patient Safety states that adverse medical events result in 210,000 to 400,000 deaths per year and 10 to 20 times those numbers of serious harms.

Since the paper disparages the medical profession, it has received a lot of media attention.

Most articles about it simply regurgitate the dismal estimates without any real attempt to dig into the paper’s methods.

Let’s take a closer look.

As is true of many papers, the abstract is a bit sketchy when describing how the paper arrived at its conclusion.

The full text of the paper reveals the author found four studies that looked at what are described as preventable adverse events in US hospitals within the last seven years. All four used the Global Trigger Tool which involves the screening of records for adverse events by nurses or pharmacists and a secondary review by physicians.

Based on opinions by “experts,” the author made a key, but erroneous, assumption that all adverse events are preventable.

The basis of that assumption was apparently this statement in the methods section of a 2011 paper in Health Affairs about the Global Trigger Tool.

“Because of prior work with Trigger Tools and the belief that ultimately all adverse events may be preventable, we did not attempt to evaluate the preventability or ameliorability (whether harm could have been reduced if a different approach had been taken) of these adverse events.”

The “belief that ultimately all adverse events may be preventable” is not supported by any facts, which are not necessary I suppose if one simply has a “belief.”

Personally, I do not share the belief that all adverse events are preventable. Let me give you a few examples of why.

Aspiration of gastric contents is considered a preventable adverse event, yet I can see no way to prevent every single occurrence of aspiration. If you can, please share it with the rest of us.

Leukopenia (a dangerously low white blood cell count), which often leads to sepsis, and is a common side-effect of cancer chemotherapy could be prevented by never using chemotherapy, but is that a realistic solution?

Repeated studies of deep venous thrombosis have found that no measure, be it drug or mechanical device, is 100% effective in preventing DVTs.

Several papers addressing the use of the Surgical Care Improvement Project guidelines for prevention of surgical site infections (SSIs) after colon surgery have found that even when guideline adherence is nearly perfect, at least 8-10% of patients develop SSIs.

Sometimes adverse events are due to patient-related factors. From an editorial in JAMA Surgery commenting on a paper about SSIs:

“[W]e are left with the yet unanswered question about how to remediate the problem [SSI] beyond adherence to SCIP. Short of a large scale public health campaign to address smoking, obesity, and comorbid disease, the findings do not expose a practical way forward.”

Pop quiz.

The Journal of Patient Safety paper estimating 210,000 to 400,000 deaths due to preventable adverse events was based on four papers with a total of how many deaths?

a. 38
b. 380
c. 3,800
d. 38,000
e. 380,000

If you said “c. 3,800,” you would have only been wrong by a factor of 100. The correct answer is “a. 38.”

Adverse events and deaths due to medical errors are serious issues that need to be addressed. But inflating the incidence of the problem does nothing but further erode the already shaky confidence of the public in the medical profession.

And creating the impression that such events are totally preventable leads to unrealistic expectations and unachievable goals.

“Skeptical Scalpel” is a surgeon blogs at his self-titled site, Skeptical Scalpel.

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