Diagnostic errors more common – and more deadly – than other treatment errors

The term “medical malpractice” often brings to mind errors made during surgery or the over-administration of prescription medications.  However, a significant component of medical malpractice revolves around errors made during a patient’s diagnosis – which ultimately happen a lot more often and can be much more dangerous.

After conducting an extensive analysis of 25 years of U.S. malpractice claim payouts, researchers from Johns Hopkins Medical Center in Baltimore, Md., revealed diagnostic errors account for the largest fraction of claims and cause the most severe harm to patients overall.  In terms of financial impact, these errors resulted in the highest total of penalty payouts – amounting to $38.8 billion between 1986 and 2010.

A diagnostic error translates to a diagnosis that was missed, wrong or delayed, as discovered by further testing.  These mistakes lead to injury either as a result of failure or delay to treat the condition – or from incorrect treatment given for a mistaken diagnosis.

According to the study’s researchers, the impact and significance of diagnostic errors has been downplayed by experts, because these types of mistakes are much more difficult to pinpoint and define.

“There’s more uncertainty about diagnostic errors than there are about treatment errors,” lead study author Dr. David Newman-Toker, an associate professor of neurology at the Johns Hopkins University School of Medicine, told FoxNews.com. “It’s reasonable to say no nurse should ever administer a tenfold dose of chemotherapy or a medication to a patient allergic to that medication.  Those events are easier to keep track of and easier to measure.

“Diagnostic errors are not quite like that,” he continued. “…Instead of having a very specific time that’s documented – with a diagnostic error, you don’t find out until later when someone is injured that it happened.  That lag creates uncertainty, and that uncertainty (sparks ideas like) ‘It wasn’t reasonable for someone to have diagnosed it at the time.’  That’s where the debate starts.”

While Newman-Toker and his colleagues only examined diagnostic errors that rose to the level of malpractice payout, they estimate each year, between 80,000 and 160,000 U.S. patients suffer from potentially preventable injury or death related to medical misdiagnosis.

To get a better understanding of the impact of diagnostic error, the researchers analyzed medical malpractice payouts from the National Practitioner Data Bank – an electronic database that keeps track of payments made for malpractice settlements since 1986.  Out of the 350,706 paid claims, diagnostic errors were the leading type of claims paid out, accounting for 28.6 percent of the total. In terms of amount of money paid, diagnostic errors also compromised the biggest proportion of total payments made, accounting for 35.2 percent.

And even more disturbing, errors of diagnosis were much more dangerous to the health of the patient – resulting in death or disability almost twice as often as errors made in other categories.

Diagnostic errors also seemed to occur more frequently in outpatient care compared to inpatient care – 68.8 percent versus 31.2 percent – but diagnostic errors in inpatient care were more likely to have lethal consequences.

Three possible solutions

With such staggering statistics, Newman-Toker advised a number of solutions to help doctors and hospitals better understand the impact of diagnostic errors – and prevent them in the future.

“What everyone can get behind today is that measurement and reporting of diagnostic errors must become mandatory,” Newman-Toker said.  “The key thing here is that right now there are lots of things hospitals and health care institutions are required to report about quality and safety of the care they provide.  But diagnostic accuracy and errors are not one of them.”

He stated that a blanket policy requiring hospitals to report these statistics must go into effect.  As of now, there’s a disincentive to reporting diagnostic errors, because no hospital would want to be the first one to report on their staff’s errors, he added.

Secondly, Newman-Toker called for more research on the impact of intervention on diagnostic errors. For example, if doctors make diagnostic checklists to make sure they are not forgetting a particular diagnosis, what kind of impact will this have on patient outcomes?

But most of all, Newman-Toker said it’s extremely important to make it mandatory for doctors to start more thoroughly recording their appointments with patients.

“The single biggest thing we could do would be to record separately the presenting symptoms of the patient from the patient’s diagnosis,” he said. “Right now, one of the main reasons it’s hard to figure out diagnostic errors is because we’re only tracking the output of the diagnosis, not the input.”

As of now, if a patient goes to the doctor for chest pains, and his or her doctor prescribes an over-the-counter medication for acid reflux, the doctor only records the final diagnosis – not the patient’s initial complaint.  Then, if that patient is later rushed to the hospital and dies from a cardiac arrest, no diagnostic error is recorded, because the patient will be correctly diagnosed as having a cardiac event at the hospital and not a missed diagnosis at his or her previous doctor’s appointment.

Because of this bizarre loophole, Newman-Toker said making this change would boost researchers’ abilities to study this problem “100-fold.”

“If we did those three things: mandatory reporting of diagnostic error, allocating resources to studying the impact of error solutions, and mandating reporting of the presenting complaints, we could make a huge difference in the next decade in terms of moving this agenda forward,” Newman-Toker said.

The research was published online in BMJ Quality and Safety.