Interpreting spirometry with race-specific reference equations led to a lower Lung Allocation Score (LAS) for Black patients and higher LAS among White patients, which could potentially contribute to racially biased allocation of lung transplants.
Interpreting spirometry with race-specific reference equations led to a lower Lung Allocation Score (LAS) for Black patients and higher LAS among White patients,1 which could potentially contribute to racially biased allocation of lung transplants, according to new research published in Annals of the American Thoracic Society.
Earlier this year, the American Thoracic Society (ATS) published an official statement recommending against the use of race- and ethnicity-specific reference equations for the interpretation of spirometry, the most often used pulmonary function test (PFT).2 The recommendation changed the ATS standard following a review of the most recent evidence on race- and ethnicity-specific vs race-neutral average reference equations.
“There is growing concern that race and ethnicity-based algorithms in medicine, including PFT interpretation, have the potential to contribute to health care disparities and support the false idea that race is a biological variable,” wrote the authors of the official ATS statement, which was published in American Journal of Respiratory and Critical Care Medicine.2
The new study aimed to determine how using race-neutral vs race-specific reference equations for spirometry interpretation may affect LAS in US adults listed for lung transplant. Since 2005, the authors noted, lung transplant prioritization has primarily relied on LAS, which is determined by multiple clinical variables. Therefore, knowing the effects of race-specific vs race-neutral spirometry interpretation is important.
The retrospective analysis identified 8982 adult patients listed for lung transplant from January 2003 to February 2015, with data sourced from the United Network for Organ Sharing database. In the overall cohort of eligible patients, 90.3% were White (n = 8114) and 9.7% were Black (n = 868).
LAS was calculated for each patient based on race-neutral equations and race-specific equations.
When using a race-specific approach, there was no significant difference between percent predicted forced vital capacity (FVCpp) between White and Black patients despite a lower raw FVC in Black patients. Using a race-neutral approach, FVCpp was 4.4% higher on average among White patients and 3.8% lower among Black patients. The overall difference was 9.0 percentage points, with White patients showing a mean FVCpp of 55.7% and Black patients 46.7% when a race-neutral approach was employed.
Regarding LAS, using a race-neutral approach to spirometry interpretation led to LAS scores that were 0.6 points lower on average compared with race-specific equations among White patients. Among Black patients, a race-neutral approach led to LAS scores 0.6 points higher on average compared with a race-specific approach (P = .001).
“Notably, the difference in LAS between approaches varied according to the [race-specific] LAS and were characterized by a U-shaped (or inverted U-shaped) relationship, with differences in LAS more pronounced among those with a [race-specific] LAS between approximately 40-80,” the authors wrote.
These findings show a clear impact on LAS, the authors noted, adding that the findings are in line with previous suggestions that including race when estimating lung function could reduce Black patients’ access to lung transplants compared with White patients.
Although further research is needed to determine the impact that race-neutral testing may have on patient care, the study highlights the potential for race-specific evaluations to contribute to disparities in care.
“Our findings raise concern that a race-specific approach to spirometry interpretation may contribute to racial bias in respiratory disease through an impact on priority for lung transplant,” the authors concluded. “These results are particularly significant in the context of interest in an evidence-based understanding of how a race-specific approach influences patient care.”
1. Brems JH, Balasubramanian A, Psoter KJ, et al. Race-specific interpretation of spirometry: impact on the lung allocation score. Ann Am Thorac Soc. Published online June 14, 2023. doi:10.1513/AnnalsATS.202212-1004OC
2. Bhakta NR, Bime C, Kaminsky DA, et al. Race and ethnicity in pulmonary function test interpretation: an official American Thoracic Society statement. Am J Respir Crit Care Med. 2023;207(8):978-995. doi:10.1164/rccm.202302-0310ST