People make mistakes in any line of work, and diagnosing a medical problem is no exception. But new research shows that diagnostic errors not only aren’t rare, they’re disturbingly common. Almost all U.S. residents will be the victim of a diagnosis that is wrong, or late.

The study, by the venerable Institute of Medicine (IOM), a division of the National Academies of Sciences, Engineering and Medicine, concluded that despite the regular occurrence of diagnostic errors, they largely have been overlooked as other patient safety concern take center stage.

Diagnostic errors are medical mistakes involving inaccurate or delayed diagnoses. According to the analysis of the IOM report by KaiserHealthNews.org (KHN), such errors account for about 1 in 10 patient deaths, hundreds of thousands of adverse events suffered by hospital patients each year and are a leading cause of paid medical malpractice claims.

Mistakes occur from a wide variety of patient problems, from the rare to the routine. An example of rare is the Liberian man who went to a hospital in Dallas last year and was sent home, even though he had Ebola; a more common error might be a heart problem diagnosed as acid reflux, or information the patient was never given when an x-ray report indicated the presence of cancer.

According to the Washington Post, a “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 report offered one estimate that diagnostic errors affect at least 12 million adults each year; that’s about 5 in 100 adults who seek outpatient care.

“Reducing the number [of errors] won’t be easy,” KHN reported, “in part because there is no standard, required way to track such errors.”

Sometimes, The Post said, doctors don’t even know when they made the wrong diagnosis. “If a doctor misses something and another one figures it out, the first doctor often never hears about it,” one source told the paper.

The IOM report said solutions would depend on better medical teamwork, training and computer systems. It called for a fundamental overhaul of the whole process involved in making a diagnosis.

In other words, the medical establishment needs to cultivate the skills of communication and collaboration as much as it does scientific analysis. Just as you should treat the whole patient, not just the body part, you also should appreciate the whole treatment system, not just its parts.

As The Post reported, “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.”

Diagnostic errors happen for many reasons, the IOM found. In addition to lack of enough collaboration among clinicians, patients and their families, and limited feedback about the accuracy of a doctor’s diagnosis, the health-care culture discourages transparency and disclosure of errors.

The report, “Improving Diagnosis in Health Care,” represents the ongoing effort by the IOM to improve patient care and safety. In 1999, the institute opened eyes with “To Err is Human: Building a Safer Health System,” a document that kick-started the patient-safety movement with its estimate that as many as 98,000 patients die each year because of medical errors.

Last week’s report identified how every health-system participant must take responsibility for identifying and minimizing diagnostic errors, from computer programmers to clinicians to patients. Because data about these mistakes is elusive, the IOM calls on participants voluntarily to report them in the hope they can, as KHN said, “develop better ways to identify, reduce and learn from ‘near misses.’”

One cog in the diagnostic wheel appears to be computerized health records, which are supposed to track and help coordinate care, but often compromise efficiency and the ability to make the right diagnosis. A system used by one provider might not be compatible with another, even though the patient is treated by both. “Auto-fill” functions sometimes enter the wrong information, which can be deadly for some people, not just inconvenient. The sheer volume of inputs and alerts can overwhelm medical staff.

It’s not uncommon, for example, for an emergency department’s clinicians to spend more time inputting information into computers than taking care of patients. It’s not uncommon for an electronic health record system to issue an alert if it detects an abnormal diagnostic test result, but 7 in 10 medical staffers surveyed said they got more alerts than they could manage.

The report’s authors made clear that patients have a heavy responsibility here, too. One of the report’s authors told KHN that patients “are going to be critical to the solution,” and that “There’s a real opportunity for patients to advocate for themselves and at the same time to challenge the health care providers about the diagnosis being made.”

Helen Haskell, who formed Mothers Against Medical Error after her teenage son died when he was given the wrong medication during an otherwise routine surgery, told KHN that she was pleased the report focused on better teamwork and communication. She also emphasized that patients need better access to their records, especially hospital records, and she encouraged consumers to ask questions when given a diagnosis: What else can it be? Does this diagnosis match all my symptoms?

“If there is any question,” Haskell told KHN, “people should get a second opinion.”

The Post story offered additional advice to patients who want to get the right diagnosis:

• Be clear, complete and accurate in telling your doctor and his or her staff about your illness. When did symptoms begin? What made them better or worse? Make notes and bring them to your appointment.
• Remember what treatments you’ve tried in the past, if they helped and what, if any, side effects you experienced.
• Keep your own records of test results, referrals and hospital admissions, as well as an accurate list of your medications. Bring the list to doctor appointments and the pharmacy when you fill a prescription.
• Ask your doctor when you will get your test results, and what you should do to follow up.