It’s one of the great benefits of living in the 21st Century: knowing that, if you feel unwell, you can go to a health professional, have an accurate diagnosis, and be treated for your illness.

Generally, we can rely on those professionals and be confident that modern health systems will deliver accurate diagnostic outcomes and support.

However, a study by John Hopkins University in the United States has cast doubt on that.

It found that across all clinical settings, including hospitals, an estimated 795,000 Americans die or are permanently disabled each year due to diagnostic error.

The number of “serious harms” due to misdiagnosis is even more disturbing. Lead investigator David Newman-Toker says they could total 4 million per year.

Vascular events, infections, and cancers – dubbed the Big Three – account for 75% of the serious harms. The study found that 15 diseases account for 50.7% of the total serious harms.

Five conditions account for 38.7% of total serious harms: stroke, sepsis, pneumonia, venous thromboembolism, and lung cancer.

The overall average error rate across diseases was estimated at 11.1%, but the rate ranges widely from 1.5% for heart attacks to 62% for spinal abscesses.

Strokes were missed in 17.5% of cases.

Dr Norman Swan, who hosts The Health Report on ABC Radio, says Australian research on injuries in healthcare shows similar results to the United States, pro rata.

However, in many cases, the patient is blamed because they’ve stayed at home suffering symptoms for a long time before presenting them to a doctor.

“Can we blame patients for this?” Dr Swan asks.

Dr Newman-Toker agrees that a contributing factor is the gap between the time that a patient first experiences some kind of medical symptom, to the time they seek care.

“Data from the UK, for example, show that the patient interval is a significant contributor to diagnostic delay in cancer cases,” he says.

Dr Newman-Toker says solutions deployed at Johns Hopkins to address missed strokes include:

• Virtual patient simulators to improve front-line clinician skills in stroke diagnosis.
• Portable eye movement recordings via video goggles and mobile phones to enable specialists to remotely assist front-line clinicians in diagnosing strokes.
• Computer-based algorithms to automate aspects of the diagnostic process.
• Diagnostic excellence dashboards to measure performance and provide feedback on quality improvement. 

The researchers believe a major issue in misdiagnosis occurs during the doctor-patient consultation.

Something as simple as training doctors to listen more closely to what patients tell them could make a difference.

Dr Newman-Toker says doctors need to get back to better bedside diagnosis.

“That interaction – the act of taking histories and physical exams, some of which has become sort of a lost art in the technological progress that we’ve seen over the years – is something that we really need to restore.

“And we’ve seen that when we do this for problems like stroke manifesting as dizziness, for example, that we can actually significantly reduce the misdiagnosis rates.”

You can listen to Dr Swan’s interview with Dr Newman-Toker here. 

Related reading: John Hopkins