Race-specific spirometry interpretation may negatively bias care for Black patients

Key takeaways:

• Black patients’ lung allocation scores were lower using a race-specific vs. race-neutral equation.
• Race-neutral equations are recommended to prevent bias in care.

Using a race-specific equation to interpret lung function of patients waiting for a lung transplant may result in racial bias of transplant allocation, according to study results published in Annals of the American Thoracic Society.

“Our study found that a race-specific approach to lung function interpretation had potential to systematically bias care to the disadvantage of Black patients listed for lung transplant,” J. Henry Brems, MD, MBE, pulmonary and critical care fellow at Johns Hopkins University School of Medicine, told Healio. “Our results support the shift to using a race-neutral equation for lung function interpretation.”

In a retrospective study, Brems and colleagues analyzed 8,982 adults (90.3% white; 9.7% Black) in the United Network for Organ Sharing database for a lung transplant to understand how using a race-specific reference equation for interpreting spirometry can impact the lung allocation score for Black and white patients.

To assess the difference between a race-specific approach and a race-neutral approach, researchers figured out a patients’ lung allocation score using an equation for each one. This involved using the Global Lung Function Initiative (GLI) equation that either matched the patients’ race or the equation that did not take this into account (GLI “Other”) to determine percent predicted FVC.

With use of a race-specific approach, precent predicted FVC was not found to significantly differ between both groups of patients (white, 51.3% vs. 50.4%), but a race-neutral approach yielded significant differences. Using this equation, researchers found that white patients’ mean percent predicted FVC increased by 4.4% (55.7%), whereas Black patients’ mean percent predicted FVC dropped by 3.8% (46.7%; P < .001).

Greater lung allocation scores were found among Black patients vs. white patients in both the race-specific approach (43.8 vs. 41.9) and the race-neutral approach (44.3 vs. 41.3; P < .001 for both), according to researchers.

When comparing the approaches among white patients, researchers found that their lung allocation score decreased by 0.6 points with use of the race-neutral vs. race-specific approach, whereas for Black patients, lung allocation scores went up by 0.6 points when the race-neutral vs. race-specific approach was used (P < .001).

Four different diagnoses — obstructive lung disease, pulmonary vascular disease, cystic fibrosis/immunodeficiency disorder and restrictive lung disease — were evaluated in subgroup analysis, in which researchers observed the greatest differences in lung allocation scores using a race-neutral approach among patients with pulmonary vascular disease (–0.71 vs. +0.7; P < .001), as well as those with restrictive lung disease (–0.78 vs. +0.68; P < .001).

“Although it was not the main finding of our study, I was surprised to see that the greatest differences in percent predicted lung function between a race-specific and race-neutral approach occurred for patients with the highest underlying lung function,” Brems said. “That has important implications for lung transplant because it may mean that a race-specific approach has the greatest potential to racially bias care at earlier stages of disease, such as the timing of when a patient is initially referred to a pulmonologist or to a transplant clinic.”

Researchers additionally assessed white and Black patients’ predicted survival both on the waiting list and after transplantation. Comparing both approaches, researchers observed that predicted survival on the waiting list increased by 3.3 days for white patients with the race-neutral approach, whereas this went down by 3.3 days for Black patients (P < .001).

With the race-neutral approach, white patients also saw an increase in predicted survival after transplantation (+0.3 days), whereas Black patients saw a decrease in predicted survival (–0.3 days; P < .001).

“Future studies will need to investigate the broader impact of a shift to race-neutral equations, including how it affects not only respiratory disease management and outcomes but also things such as disability benefits and employment eligibility,” Brems told Healio. “As part of that, studies may need to investigate how best to use lung function estimates (and what other measures to incorporate) when making these decisions.”

Reference:

• Race-neutral testing could have given access to life-saving lung transplants for more Black patients. https://www.thoracic.org/about/newsroom/press-releases/journal/2023/race-neutral-testing-and-lung-transplants.php. Published June 23, 2023. Accessed June 23, 2023.

For more information:

J. Henry Brems, MD, MBE, can be reached at jbrems2@jhu.edu.