Last week saw the arrival of some truly devastating new statistics. A study led by Professor James M. Naessens (MPH, ScD) at the Mayo Clinic found that over 20 percent of patients with serious conditions were first misdiagnosed.
Naessens and his team studied patients who had gone to the Mayo Clinic seeking second opinions from top doctors. The setup of the study was simple: Naessen’s team simply compared the first and second opinions to see how often medical professionals came to the same conclusion.
And that’s where things get a little ugly. They discovered that 1 in 5 second opinions were “distinctly different” than the original diagnoses. In more than 70 percent of cases, Mayo Clinic doctors were able to improve upon the first diagnosis. This means that doctors only agreed completely on about 12 percent of the patients who were studied.
Not a New Problem
Unfortunately, this underwhelming success rate is hardly surprising, and not simply because patients at the Mayo clinic have more challenging cases. Many other studies have shown that diagnoses of average patients leave plenty to be desired.
A 2014 report found that as many as 1 in 20 U.S. adults are misdiagnosed in standard outpatient visits. That equates to a staggering 12 million people each year. In about half of those cases, patient outcomes could be worsened by the misdiagnosis.
In fact, 2013 research out of Johns Hopkins Medicine found that misdiagnosis is actually the most common and most costly form of medical malpractice. It is also the deadliest. Over 25 years, misdiagnosis resulted in death twice as often as other types of malpractice. The report estimates that misdiagnosis leads to as many 160,000 U.S. deaths per year.
Of course, this data was later updated in early 2016, when Hopkins published a new study claiming that medical errors – such as misdiagnoses – are the third-leading cause of death, killing 250,000 Americans each year.
The Mayo Clinic study also found that women are more likely to be misdiagnosed. Worse still, previous research has found that children are more often the victim of diagnostic error than adults. Cerebral Palsy and other birth injuries are some of the more serious and frequent conditions that are missed in pediatric cases.
Examining All of the Costs
In addition to this tragic human cost, misdiagnosis is a heavy financial burden on the health care system. The Mayo Clinic findings point to the added costs that result from an early misdiagnosis. Many of the patients required additional tests or developed complications from delayed or misguided treatment.
This sort of misdiagnosis, sometimes called under-diagnosis, is just half of the problem. The problem’s opposite, over-diagnosis, is another common and costly issue. For example, misdiagnosis of breast cancer alone costs Americans $4 Billion each year, according to a 2015 study published in Health Affairs. In those cases, too much testing leads to false positives and unnecessary treatment.
The Bottom of the Iceberg
Given the scale of the problem, it seems remarkable that so little attention is paid to misdiagnosis. The public imagination, not to mention the media, fixate on dangers that cause only a tiny fraction of 160,000 deaths per year. It seems unlikely that the system will ever improve if people continue to underestimate the impact of misdiagnosis. This is why studies like Naessens’s are so very important.
Dr. David Newman-Toker of Johns Hopkins, commenting on their 2014 study, addressed how something so hazardous is routinely ignored. He explained that, while misdiagnosis is statistically “the biggest patient-safety problem, it’s the bottom of the iceberg.” In other words, it remains hidden because other types of malpractice capture more attention from the media and the public. “These are frequent problems that have played second fiddle to medical and surgical errors, which are evident more immediately.” While it makes for sensational news stories when surgical instruments are left inside patients, the reality is that misdiagnosis is far more likely to harm the average person.
What Can Be Done?
Misdiagnosis is a problem with many causes and no easy solution. One reason researchers have focused on malpractice like surgical errors, is that sometimes they can be relatively cheap and easier to fix. Hospitals can reduce the number of materials left inside surgical patients by tracking surgical instruments and sponges for a few dollars per operation.
Misdiagnosis, on the other hand, has not benefitted from such a quick fix.
Naessens, lead author of the Mayo Clinic study, doesn’t sugarcoat the situation: “Diagnostic error is an area where we need more research, more study and more information,” he said. With such shocking findings, it is possible such research will indeed raise awareness about the risks of misdiagnosis and people will push for improvement.
In the meantime, Naessens hopes patients and their families take note of the study’s conclusions. “The second opinion is a good approach for certain patients to figure out what’s there and to keep costs down.”