WASHINGTON — Most Americans who go to the doctor will get a diagnosis that is wrong or late at least once in their lives, sometimes with terrible consequences, according to a report released Tuesday by an independent panel of medical experts.
This critical type of health care error is far more common than medication mistakes or surgery on the wrong patient or body part. But until now, diagnostic errors have been a relatively understudied and unmeasured area of patient safety. Much of patient safety is focused on errors in hospitals, not mistakes in diagnoses that take place in doctors’ offices, surgical centers, and other outpatient facilities.
The new report by the Institute of Medicine, the health arm of the National Academy of Sciences, outlines a systemwide problem. The report’s authors say they don’t know how many diagnostic errors take place. Some estimates say it affects at least 12 million adults each year.
‘‘Despite the pervasiveness of diagnostic error and the risk for patient harm, they have been largely unappreciated within the quality safety movement in health care and this cannot and must not continue,’’ said Victor Dzau, institute president, during a news briefing Tuesday.
What’s more, errors will likely worsen because of the growing complexity of the diagnostic process and the delivery of health care, according to the committee that conducted the study. The study is the institute’s third in a series on patient safety. Its landmark 1999 report ‘‘To Err is Human’’ dramatically exposed the number of deaths — as many as 100,000 a year in hospitals — because of errors in medical treatment.
But that report and a subsequent one barely mentioned errors in the diagnostic process.
Part of the problem, experts say, has been the difficulty of measuring such mistakes.
‘‘The data on diagnostic errors are sparse, few reliable measures exist, and often the error is identified only in retrospect,’’ said John R. Ball, chairman of the committee and executive vice president emeritus of the American College of Physicians. Sometimes that only happens after autopsies, or as a result of medical malpractice suits.
The stereotype of one physician considering a patient’s case and coming up with a diagnosis is not always accurate, he said. Often it happens because of errors in the health care system. Fixing the problem will require nothing short of a fundamental overhaul of the entire process of how a diagnosis is made, the committee authors said.
Experts say diagnosis is one of the most difficult and complex tasks in health care because it involves patients, clinicians, thousands of lab tests, and more than 10,000 potential diagnoses.
‘‘It crosses so many different domains in the practice of medicine, which makes it complicated by itself,’’ said Paul Epner, executive vice president of the Society to Improve Diagnosis in Medicine, a nonprofit, physician-led organization patient safety group. The advocacy group petitioned the IOM to produce the report.
Diagnostic errors result from a variety of causes, the committee found. They include inadequate collaboration among clinicians, patients, and their families; limited feedback to clinicians about the accuracy of their diagnoses; and a health care culture that discourages transparency and disclosure of errors.
One example cited in the report was about a woman, identified only as Carolyn, who arrived in the emergency room with chest pain and pain down her left arm and other classic symptoms of a heart attack. But her tests were normal, and the clinician told her she had acid reflux. A nurse even told her to stop asking questions of the doctor ‘‘because he doesn’t like to be questioned,’’ the woman said in a video clip.
The woman was released a few hours later, feeling embarrassed about making a fuss. But over the next two weeks, she became sicker. Initially, she worried that she might be seen as ‘‘a difficult patient.’’ But she had to return to the emergency department for a procedure to unblock her artery. Since her heart attack, she said, she had to stop working.
‘Often the [diagnostic] error is identified only in retrospect.’John R. Ball, chairman of the Institute of Medicine committee that studied the diagnostic process
The report also said that health information technology may be contributing to diagnostic errors. More doctors’ offices and health systems now have electronic health records, but clinicians often complain the systems are hard to use.
Doctors often don’t know when they have made the wrong diagnosis, said Tejal Gandhi, president of the National Patient Safety Foundation, and an internal medicine doctor for 15 years.
Often the scenario involves a physician missing something and a patient, who doesn’t get better, seeking a second opinion. Something that was missed is picked up, and the first doctor never hears about it, said Kavita Patel, a policy expert at the Brookings Institution’s Center for Health Policy and a primary care doctor at Johns Hopkins Medicine.
The report said health care organizations need to put systems in place to identify diagnostic errors and near misses. They also need to adopt a nonpunitive culture so open discussion and feedback can take place. That could be empowering for frontline workers like medical assistants to act as a check and balance.