A new study published last week in JAMA Dermatology suggests that doctors are often influenced by a patient's initial diagnosis when offering a second opinion—potentially undermining the notion that "two heads are better than one" when seeking diagnoses.
Study details and key findings
For the study, researchers from UCLA Health asked 149 pathologists to interpret skin biopsies from 90 patients with slides that ranged from benign to invasive melanoma. The pathologists were asked to interpret the slides in two different phases.
In the first phase, they were asked to interpret biopsies with no information from another pathologist's evaluation. Over a year later, the pathologists were asked to interpret the same biopsies. However, the researchers did not inform participants that they were evaluating the same samples. In addition, the pathologists received another pathologist's initial diagnosis with some of the slides.
"In other words, the pathologists were providing a second opinion, but they only knew the first opinion diagnosis for a randomly-selected subset of the cases," said Joann Elmore, lead study author and a professor of medicine in the general internal medicine division at the David Geffen School of Medicine at UCLA.
The study authors found that pathologists were more likely to offer a more severe diagnosis when they were told the initial diagnosis was severe, and they were more likely to offer a less severe diagnosis when they believed the initial diagnosis was not severe.
"When information on a first opinion was shared, it was always either more or less severe than the pathologist's own diagnosis in the first phase," Elmore noted.
Notably, this pattern even occurred among participants who claimed they were "not at all influenced" by an initial diagnosis, the study authors found.
According to the study authors, the primary concern with their findings is that a patient's treatment can be either too robust or weak when a physician's opinion is swayed by an initial diagnosis.
The notion that "two heads are better than one" should be approached with caution when making medical diagnosis, the study authors noted. In particular, the study underscores the importance of refining the process physicians use when making a medical diagnosis.
"The extensive amount of sway noted in this study points to the complexities of the diagnostic process. A concerning finding of this study was that knowledge of the first diagnoses also swayed pathologists away from correct diagnoses," Elmore said. "Physicians providing second opinions should be blinded to the first opinions if the goal is to obtain an independent diagnostic opinion." (Bean, Becker's Hospital Review, 8/15; UCLA Health news release, 8/10; Elmore et al., JAMA Dermatology, 8/10)