Researchers examine how influenced dermatopathologists are by the opinions of their colleagues.
Dermatopathologists providing a second opinion on a diagnosis should be automatically blinded to the first opinion, say the authors of a study finding that first opinions can sway second opinions even away from the correct diagnosis.
A randomised controlled trial, published in JAMA Dermatology, attempted to determine just how influenced dermatopathologists were by the opinions of their colleagues, and what effect this could have on patient outcomes.
In the study’s first phase, researchers asked 149 dermatopathologists to each give a diagnosis on a slide set of 18 melanocytic skin biopsy specimens that were a random selection ranging from from benign or mildly dysplastic nevi to malignant invasive melanoma.
Each of those slides – there were 90 in total – had also been reviewed by a separate consensus panel of three dermatopathologists who were considered experts in melanocytic lesions.
After a one year “washout period”, those same 149 dermatopathologists were once again asked to review the same slide set as they were shown in phase I – acting in effect as their own controls – but this time some were told of the prior diagnoses made for their slides.
Despite nearly one-third of participants declaring at the outset that they were not at all influenced by first opinions, the study revealed that many were indeed swayed into giving either a higher or lower diagnosis on the same slide they had reviewed one year ago.
If the first opinion on the slide gave a lower diagnosis, there was a 38% higher likelihood that the dermatopathologist would also give a lower classification than they had one year ago. If the first opinion gave a higher classification, then the participant was 52% more likely to also give a higher classification than they had given that same slide a year ago.
The findings were similar even when the analysis was limited to the dermatopathologists who considered themselves immune to the effects of prior opinions.
The study also found that even when the dermatopathologist’s decision in phase I was backed up by the independent consensus panel, they were still swayed by prior opinion in the second phase of the study.
“Knowledge of the first person’s diagnosis lowers the accuracy,” Professor Joann Elmore, lead author on the study and a professor?of medicine in the David Geffen School of Medicine at the University of California, Los Angeles told The Medical Republic.
“It causes them to not give an accurate diagnosis – they are swayed up and down, when they started off with an accurate diagnosis.”
Professor Elmore says the findings suggest that second opinions in dermatopathology should be blinded, so that the second dermatopathologist is not aware of the diagnosis made by the first.
“The clinicians said that when they do know the first person’s diagnosis, they’re more likely to want to coalesce around that to not upset that person and they want to provide support to that person,” she said.
Dermatopathologist Dr Nima Mesbah Ardakani, from PathWest in Perth, said there was some merit to the suggestion that dermatopathologists giving a second opinion be blinded to a first opinion.
He agreed dermatopathologists could be influenced by a prior diagnosis – possibly out of respect for a colleague’s judgement – which was why he and his colleagues made a point of only looking at the first opinion on a slide after they had made their own.
However, he said it was still important to know what the first opinion had been, particularly as dermatopathology was complex and there was always an element of subjectivity to a diagnosis.
“If there is a significant difference impacting patient management, you obviously want to be quite clear about our opinion about the case,” he said.
Dr Mesbah Ardakani also noted that the choice of pathology – melanocytic lesions – would have meant there was more inter-observer variability because it was a difficult and complex diagnosis.
However the introduction of molecular pathology would likely help reduce that subjectivity, he said.
