Second opinions important, study suggests

More than 20 percent of patients who sought a second opinion at one of the nation’s premier medical institutions had been misdiagnosed by their primary care providers, according to research recently published.

Twelve percent of the people who asked specialists at the Mayo Clinic in Rochester, Minnesota, to review their cases had received correct diagnoses, the study found. The rest were given diagnoses that were partly in line with the conclusions of the Mayo doctors who evaluated their conditions.

The results are generally similar to other research on diagnostic error but provide additional evidence for advocates who say such findings show that the health-care system still has room for improvement.

“Diagnosis is extremely hard,” said Mark L. Graber, a senior fellow at the research institute RTI International and founder of the Society to Improve Diagnosis in Medicine. “There are 10,000 diseases and only 200 to 300 symptoms.”

Graber was not involved in the Mayo Clinic research, which appears in the Journal of Evaluation in Clinical Practice. He estimates that the rate of misdiagnosis, although difficult to determine, occurs in 10 percent to 20 percent of cases.

“Diagnostic error is an area where we need more research, more study and more information,” said James M. Naessens, a professor of health services research at the Mayo Clinic, who led its study. “The second opinion is a good approach for certain patients to figure out what’s there and to keep costs down.”

The researchers looked retrospectively at 286 patients who had seen primary-care physicians, physician assistants and nurse practitioners in 2009 and 2010. Nearly twothirds were younger than 64, and most were female.

With or without the help of their initial provider, those people sought additional advice from the Mayo Clinic’s internal medicine department. That makes the group somewhat different from the general population, Naessens said, because their conditions were serious enough to merit another look by some of the best physicians in the country.