Wednesday, June 11, 2008

Redefining medical error

Words mean things. They influence our perceptions and how we think. We must be careful how we use them. One example of careless use of words is the confusion of denotation and connotation. A word’s denotation is its official or formal meaning. Its connotation, an implied meaning or an emotional reaction it elicits, may be something entirely different. We’re all familiar with the notion of bad connotation.

The word error has traditionally had a bad denotation and a bad connotation. Some synonyms of error (wrongdoing, fault) point the finger of blame. Others (screw-up, blooper) mean incompetence. Our wise and all-knowing medical thought leaders have redefined (changed the denotation of) error to mean adverse event. Unfortunately neither these thought leaders, the media nor consumer activist groups have done anything to rid this newly defined word of its former connotation. The redefinition of medical error is an unfortunate example of carelessness in the use of words, which has cost the profession dearly in public confidence. In today’s Newspeak the tragic death of John Ritter is considered medical error. Ironically this all comes at a time when the patient safety advocates claim they are trying to move away from a culture of blame.

By and large the redefinition of medical error started with the IOM report To Err is Human. Although lauded as a seminal document in the patient safety movement the report was criticized in an important but long forgotten NEJM article:

Yet a careful reader must have some reservations about the IOM report. The report states that errors cause between 44,000 and 98,000 deaths every year in American hospitals. I was prompted by this statement to look up the definition of error. The American Heritage College Dictionary, third edition, defines an error as a deviation from that which is generally held to be acceptable. More telling are the synonyms given in the Merriam–Webster Thesaurus: blooper, blunder, boner, bungle, goof, lapse, miscue, misstep, mistake, and slip-up. The prevention of errors through analysis of human factors has a specific definition in the engineering literature, and the introduction of the science of error prevention in health care is an extremely important advance. The combination of the strikingly large numbers of errors cited by the report and the connotations of the word "error" create an impression that is not warranted by the scientific work underlying the IOM report.

The author of this piece, Troyen A. Brennan, M.D., J.D., M.P.H., should know about that body of scientific work. He and his colleagues conducted the research! Dr. Brennan cites examples of the IOM report misinterpreting his research in the redefining of medical error:

In both studies, we agreed among ourselves about whether events should be classified as preventable or not preventable, but these decisions do not necessarily reflect the views of the average physician and certainly do not mean that all preventable adverse events were blunders. For instance, surgeons know that postoperative hemorrhage occurs in a certain number of cases, but with proper surgical technique, the rate decreases. Even with the best surgical technique and proper precautions, however, a hemorrhage can occur. We classified most postoperative hemorrhages resulting in the transfer of patients back to the operating room after simple procedures (such as hysterectomy or appendectomy) as preventable, even though in most cases there was no apparent blunder or slip-up by the surgeon. The IOM report refers to these cases as medical errors, which to some observers may seem inappropriate.

Perhaps more to the point, neither study cited by the IOM as the source of data on the incidence of injuries due to medical care involved judgments by the physicians reviewing medical records about whether the injuries were caused by errors. Indeed, there is no evidence that such judgments can be made reliably.

The NEJM article goes on to point out other distortions in the IOM report. The criticism deserves to be taken seriously, coming as it does from an author of both of the studies upon which the IOM report is based!

Recently the classification of all patient falls and decubitus ulcers as medical errors has taken the idea to an even more ridiculous extreme.

Finally, last Saturday the American Medical Informatics Association held it’s first ever meeting on Diagnostic Error in Medicine. Bob Wachter, the keynote speaker, believes this meeting will give the field of diagnosis, which has gained relatively little attention in patient safety initiatives, the respect it deserves. He notes in his blog:

Is there any hope of getting diagnostic errors included under the broad umbrella of patient safety, where they can garner the attention and resources they deserve? Sure. But we need to solve a chicken-or-egg problem: if there is no interest and funding in the topic, we won’t generate the research we need to measure the toll of the problem or come up with effective solutions. And then there won’t be funding and interest.

Clearly the problem of misdiagnosis needs more attention. However we must be careful when we adjudicate misdiagnosis as error. Some examples, such as John Ritter’s aortic dissection, are unavoidable. The art and science of diagnosis will garner more attention in the patient safety literature. That will be a good thing provided continued careless use of the word error does not perpetuate a culture of blame.

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