Survey Calls Out Implicit Bias in Peripheral Vascular Care

Even among physicians who believe they are doing the best they can for their patients, implicit bias can adversely impact clinical decisions and contribute to low-value care for Black patients with peripheral vascular disease, a new survey shows.

When clinical registry data on patients were linked to the performance of vascular providers on a race implicit association test (IAT), there was a significant interaction between physician bias and patient race and the care provided. Black patients with claudication were more likely to undergo an infrapopliteal procedure if their physician had a pro-white bias. Both white and Black patients of physicians with no perceived bias, on the other hand, were less likely to receive an infrapopliteal procedure for claudication in comparison.

The survey findings add to prior research showing that Black men and women have about a 10% higher lifetime risk of developing PAD than white patients, are more likely to undergo peripheral vascular interventions for newly diagnosed claudication despite guidelines cautioning against it, and are less likely to receive preamputation vascular care or guideline-directed medical therapy that could prevent an amputation.

Corey A. Kalbaugh, PhD (Indiana University School of Public Health–Bloomington), who led the survey, told TCTMD that it was an attempt to unpack some of “the why” behind the known racial disparities.

“These aren't just numbers. These are real people, . . . and there are solutions to the problem,” he noted. “At a system level, we're not doing the best we can to ensure that the best care is offered to all people.  I do think physicians should consider their own practices and where they're falling short of standards, but I also think the kind of changes that we really need can come at the level of the healthcare system.”

In the paper, published this week online ahead of print in JAMA Surgery, Kalbaugh and colleagues say healthcare systems and insurance providers should routinely be reviewing their data to look for instances of disparate care that affect patient outcomes and work toward multilevel interventions, including those built into electronic health records that provide a way of objectively monitoring care and initiating feedback for physicians to act upon.

A quality-improvement trial that used this type of methodology successfully mitigated Black-white disparities when it was used in patients with early-stage cancers.

Survey Says . . .

The implicit bias survey was offered to members of the Vascular Quality Initiative (VQI) and resulted in participation from 218 vascular specialists (mean age 46 years; 26% female). As a group they were 66% non-Hispanic white, 5% non-Hispanic Black, 4% Hispanic, and 25% other race or ethnicity.

The 10- to 15-minute online IAT uses photos, positive and negative words, and reaction time to assess underlying perception biases and calculate a score. The VQI was then used to link the specialists to their procedure- and patient-level data.

Based on IAT scores, the physicians were grouped into categories of observed racial preference: strong, moderate, or slight pro-white bias, no bias, and slight, moderate or strong pro-Black bias.

The majority of physicians (72%) exhibited a pro-white bias, 17% had no specific preference for Black or white individuals, and 11% had a pro-Black bias. In those with pro-white bias, the degree of implicit bias was slight in 25%, moderate in 45%, and strong in 31%. In those with pro-Black bias, the degree of bias was slight in 43%, moderate in 43%, and strong in 13%.

That to me was the most exciting thing about this survey [because] there is a group of people who really seemed to be treating people the same. Corey A. Kalbaugh

Looking at the impact on patient care, Black patients with claudication treated by a physician with pro-white bias were more likely to undergo an infrapopliteal procedure compared with the total sample (adjusted OR 1.67; 95% CI 1.12-2.48). White patients with claudication who were treated by physicians with pro-white bias or no bias were less likely to have an infrapopliteal procedure (adjusted OR 0.84; 95% CI 0.70-1.01 and adjusted OR 0.76; 95% CI 0.63-0.90, respectively).

Amputation rates also were impacted by implicit bias, with increased odds at 1 year seen in Black patients of a specialist with pro-white bias (adjusted OR 2.34 vs white patients; 95% CI 1.20-4.55).

When Black patients were treated by a specialist with no bias, their odds of an infrapopliteal procedure for claudication and of amputation within 1 year were similar to those of white patients.

Drivers of Bias and Low-Value Care

In an accompanying editorial, Jason M. Johanning, MD (University of Nebraska Medical Center, Omaha), notes that while the survey’s results are provocative, it does not examine causative factors for disparate treatment.

“Specifically, a physician’s practice environment markedly impacts treatment of Medicare patients with PAD, with tibial interventions for claudication more likely to occur with male sex, Black race, diabetes, and a never-smoking status,” Johanning says. “In addition, the physician characteristics of early career status, office-based ambulatory setting, and high-volume practice were significantly associated with tibial intervention for claudication.”

However, the biggest modifiable driver of disparities, Johanning adds, is likely reimbursement.  “Currently, there is a perverse incentive to intervene in patients with tibial disease and claudication,” he writes. “Unfortunately, the slippery slope of financial bias cannot be ignored.”

To TCTMD, Kalbaugh said that while he wasn’t surprised by the survey findings, they show that even among dedicated professionals participating in a quality improvement database like VQI there are unseen personal biases contributing toward poor care.

While Johanning’s points are well taken, he added,  ”my challenge back to that would be to ask why these high-risk, low-value procedures are being performed more frequently on Black patients than white patients. Why is a physician who has a pro-white bias more willing to do a procedure with high reimbursement but poor outcomes for their Black patients than their white patients?”

Kalbaugh said that another interesting question the survey raises is: who are those 17% of participants exhibiting neither pro-white nor pro-Black bias? Better understanding of who they are and how they work might provide clues to helping close gaps in care.

“That to me was the most exciting thing about this survey [because] there is a group of people who really seemed to be treating people the same,” Kalbaugh said.