Historical perspective on medical errors: Richard Cabot and the Institute of Medicine.

The November 1999 report from the Institute of Medicine (IOM), “To Err Is Human,” stated the surprising estimate that errors by the medical profession are the eighth leading cause of death in the United States. The report called for a nationwide directive to address patient safety. The Institute, which is composed largely of health care administrators, recommended mandatory reporting of adverse events, heightened standards by oversight organizations, and expansion of safety systems within health care organizations. To support these recommendations, the IOM report estimated that between 44,000 and 98,000 deaths occur annually in American hospitals as a result of medical error. This startling estimate aroused substantial government and public concern for patient safety and certainly seized the attention of the medical profession. Although the stated goal of the report was to show that a system, despite being wellintentioned, could produce significant errors and that such errors could and should be combated by addressing flaws within the system, many physicians condemned the report. Most rebuttals disputed the true incidence of error-related mortality, and virtually all challenges to the IOM emphasized the competency and dignity of the medical profession. Although the IOM report has had a significant impact, it was not the first attempt to confront medical errors in American medicine. Nearly 100 years ago, Richard Clark Cabot, a Harvard physician, published two studies that examined the rates of error in clinical diagnosis. Although the science and technology of medicine have made remarkable progress since Cabot’s time, the fears and apprehensions of physicians in response to his work were remarkably similar to those recently expressed by many members of our profession. Such anxieties are, as they were then, a major impediment to improvement in health care. The purpose of this discussion is briefly to compare and contrast the response of the medical profession to the Cabot reports from the early 1900s with the current response to the IOM report. Around the turn of the last century, Richard Cabot was a practicing physician prominent in the Harvard hospital system. Cabot’s first article on medical errors, “A Study of Mistaken Diagnosis Based on the Analysis of 1,000 Autopsies and a Comparison with the Clinical Findings,” appeared in JAMA in 1910. This report recounted his personal review of 1,000 clinical records of patients who had recently died in the Massachusetts General Hospital. For each patient, he compared his clinical diagnosis, which he obtained on review of the medical records, with the postmortem findings evident at autopsy. Any disparity between his clinical diagnosis and the autopsy findings was categorized as a diagnostic error. Cabot found significant error in the premortem diagnoses, especially in such areas as cardiovascular disease and acute nephritis. He concluded not with a condemnation of physicians or their motivation. Instead, Cabot considered his report compelling evidence that the medical profession of his day held a multitude of false assumptions that flawed the diagnostic acumen of physicians. In 1912 Cabot published a second report, in which he reviewed an additional 2,000 cases. Again he identified significant disagreement between the premortem diagnosis and the postmortem findings. The tone of this second report was considerably bolder. Where Cabot had made only nonthreatening observations about diagnostic inconsistencies in 1910, he now described grave systemic errors in the practice of medicine. He was careful to point out that such errors were not the result of incompetence: