When a physician disclosed having specialty bias, patients were more likely to opt for the treatment associated with that physician's practice and to have increased levels of trust, according to the results of both an observational study and a randomized controlled laboratory experiment.

Based on observational field work, patients who heard their surgeon explicitly disclose specialty bias had higher likelihoods of choosing surgery than patients who did not hear their surgeons disclose bias (RR 2.07, 95% CI 1.47-2.92).

The research, by Sunita Sah, PhD, MS, of the Johnson Graduate School of Business at Cornell University in Ithaca, NY, and colleagues, was published in PNAS. The authors note that since it is more common for such disclosure of bias to be examined in the context of other industries such as finance, insurance, and healthcare, this study's clinical setting makes it unique.

Action Points Note that this series of studies, one of which was a randomized trial, demonstrated that physician disclosure of potential bias toward one of two equal treatment options increased levels of patient's trust.

Be aware that the trial and observational cohort were limited to patients with slow-growing prostate cancer.

The randomized controlled laboratory experiment suggested that there were significant differences in the levels of trust between those who were and were not exposed to bias disclosure. The data revealed that the trust of those in the disclosure group (M=5.65 on a 7-point Likert scale, 95% CI 5.50-5.79) was significantly higher than the trust of those in the control group (M=5.44, 95% CI 5.29-5.59).

"We all need to be careful when disclosing bias or conflicts of interest because of the potential consequences," Sah commented, adding that this is especially true in a face-to-face setting, like that of a doctor's office.

Observational data for the study were based on 219 patients from four separate Veterans Affairs hospitals. Patients' interactions with surgeons were recorded, and printed in transcript form. The men were all informed that they had prostate cancer, that their level of prostate-specific antigen (PSA) was less than 20 ng/mL, and that their Gleason score was 6 or 7. Out of the 219 patients, 35 (16%) were exposed to a disclosure of specialty bias towards surgery. After a period of 6 months, a decision was made as to whether the patient should or should not have surgery, or have an alternative treatment.

The other part of the study, which included 447 men, was conducted in a laboratory setting. These men were randomly assigned to a control or disclosure group. Both groups watched videos in which actor-physicians reported a diagnosis of slow-growing prostate cancer, but specialty bias was only specifically acknowledged in the disclosure group.

The exact phrase that was added in the disclosure group was, "Remember, I am a surgeon, so I know more about surgery than radiation." The wording was based on actual commentary of physicians who were recorded as part of the observational study.

"In all our models with our experiment, we find a significant positive relationship between surgeons disclosing bias and patients choosing surgery," Sah and co-authors reported. These findings are important not only for physicians to keep in mind, but also for patients to be aware of when considering various treatment options.

There was not a significant difference between the groups in the number of men who said they would see a radiation oncologist before making their decision. However, when the patients were ultimately asked to choose between surgery and other forms of treatment, those in the disclosure group were more likely to opt for having surgery (74%) than those in the control group were (64.7%).

The researchers proposed that moving forward, patients should be given educational materials to help ease their decision-making. The team also suggested recruiting an oncologist without a specialty in surgery or radiation to help facilitate discussions and aid patients' decision-making. Such a third party could help eliminate the consequences of the initial disclosure bias.

The authors reported that they had no conflict of interest.