“I consider myself lucky to be alive,” said Brook, now 72, of the 2006 ordeal, which he described at a recent international conference on diagnostic mistakes held in Baltimore. A physician for 40 years, Brook said he was “really shocked” by his misdiagnosis.
But patient safety experts say Brook’s experience is far from rare. Diagnoses that are missed, incorrect or delayed are believed to affect 10 to 20 percent of cases, far exceeding drug errors and surgery on the wrong patient or body part, both of which have received considerably more attention.
Recent studies underscore the extent and potential impact of such errors. A 2009 report funded by the federal Agency for Healthcare Research and Quality found that 28 percent of 583 diagnostic mistakes reported anonymously by doctors were life-threatening or had resulted in death or permanent disability. A meta-analysis published last year in the journal BMJ Quality & Safety found that fatal diagnostic errors in U.S. intensive care units appear to equal the 40,500 deaths that result each year from breast cancer. And a new study of 190 errors at a VA hospital system in Texas found that many errors involved common diseases such as pneumonia and urinary tract infections; 87 percent had the potential for “considerable to severe harm” including “inevitable death.”
Misdiagnosis “happens all the time,” said David Newman-Toker, who studies diagnostic errors and helped organize the recent international conference. “This is an enormous problem, the hidden part of the iceberg of medical errors that dwarfs” other kinds of mistakes, said Newman-Toker, an associate professor of neurology and otolaryngology at the Johns Hopkins School of Medicine. Studies repeatedly have found that diagnostic errors, which are more common in primary-care settings, typically result from flawed ways of thinking, sometimes coupled with negligence, and not because a disease is rare or exotic.
The problem is not new: In 1991, the Harvard Medical Practice Study found that misdiagnosis accounted for 14 percent of adverse events and that 75 percent of these errors involved negligence, such as a failure by doctors to follow up on test results.
Despite their prevalence and impact, such mistakes have been largely ignored, Newman-Toker and others say. They were mentioned only twice in the Institute of Medicine’s landmark 1999 report on medical errors, an omission some patient safety experts attribute to difficulties measuring such mistakes, the lack of obvious solutions and generalized resistance to addressing the problem.