A study published in the Journal of Evaluation in Clinical Practice on April 4, 2017, found that more than 20 percent of medical patients are misdiagnosed. The study titled "Extent of Diagnostic Agreement Among Medical Referrals" looked at the diagnosis originally given to patients and compared that to the diagnosis later given upon the patient seeking a second opinion.
The study reviewed the records of 286 patients who were referred by their primary care doctor to the Mayo Clinic's General Internal Medicine Division in Rochester, Minnesota, over a two-year period from Jan. 1, 2009 to Dec. 31, 2010.
Overall, the results showed only 12 percent of those seeking a second opinion at the Mayo Clinic had their diagnoses confirmed. However, 21 percent of the patients had their diagnosis completely changed, while 66 percent of those patients received a refined or redefined diagnosis. Overall, the study showed that almost 88 percent of patients seeking a second opinion at the Mayo Clinic receive a new or refined diagnosis.
Previous research cited in the new study showed that errors in diagnosis "...contribute to approximately 10 percent of patient deaths." Additionally they "account for 6 to 17 percent of adverse events in hospitals."
"Effective and efficient treatment depends on the right diagnosis," said study co-author James Naessens, a health care policy researcher at the Mayo Clinic, in an April 4th press release in Science Daily. "Knowing that more than 1 out of every 5 referral patients may be completely [and] incorrectly diagnosed is troubling -- not only because of the safety risks for these patients prior to correct diagnosis, but also because of the patients we assume are not being referred at all."
In a Washington Post article, Mark L. Graber, a senior fellow at the research institute RTI International and founder of the Society to Improve Diagnosis in Medicine, who was not involved with the study noted, "Diagnosis is extremely hard. There are 10,000 diseases and only 200 to 300 symptoms." He added, "Doctors are humans, and they make the same cognitive mistakes we all make. If you are given a serious diagnosis, or you’re not responding the way you should [to medication], a second opinion is a very good idea. Fresh eyes catch mistakes."
Second opinions are still encouraged, but the concern is that they may be limited due to in-network insurance issues preventing patients from seeking second opinions. In response to the problem of diagnosis error, the National Academy of Medicine has called for dedicated federal funding for improved diagnostic processes and error reduction.
It is obvious that there is an increase in cost both in diagnosis and medical treatment if the first diagnosis is not confirmed by the second opinion. However, Naessens sums up the concerns if a second opinion is not sought saying, "Total diagnostic costs for cases resulting in a different final diagnosis were significantly higher than those for confirmed or refined diagnoses, but the alternative could be deadly."