Removing a race-based adjustment from the calculation of lung function by spirometry in children significantly increased the number of abnormal tests in Black children, including tests suggesting obstructive lung disease, a study co-led by researchers at Vanderbilt University Medical Center has found.
Their findings, published May 28 in the journal JAMA Pediatrics, suggest that the adjustment for race in spirometry resulted in an underreporting — and thus possibly undertreatment — of chronic lung diseases, including asthma and cystic fibrosis, in Black children.
“Our results will help health care providers understand what to expect when removing race from spirometry interpretation in children,” said Christian Rosas-Salazar, MD, MPH. “This is important, as race-neutral equations are relatively new, and the current recommendation is not to use race-based adjustment when interpreting spirometry results in children or adults.”
Rosas-Salazar, assistant professor of Pediatrics at VUMC, is co-author of the paper with Daniel Weiner, MD, of the University of Pittsburgh Medical Center (UPMC), and first author Eric Forno, MD, MPH, of Indiana University.
Spirometry is a technique that measures airflow into and out of the lungs, including forced expiratory volume (FEV1), or the air that is exhaled in 1 second, and forced vital capacity (FVC), the full amount of air expelled with effort in a complete breath.
The FEV1, FVC, and FEV1/FVC ratio are used to determine whether a patient with low pulmonary function has a restrictive lung disease, such as interstitial lung disease, or an obstructive lung disease, such as asthma or cystic fibrosis.
In 2012, the Global Lung Function Initiative (GLI), a network of researchers and clinicians who analyze lung function data from around the world, published race-specific reference equations (GLIR) for spirometry to account for observed differences in the level of pulmonary function among five identified racial groups.
In the United States, the idea that there are intrinsic racial (implying genetic) differences in lung function and lung capacity goes back to studies of soldiers conducted at the end of the Civil War.
Increasingly, however, researchers have challenged the notion that race has an exclusive biological basis. They have urged that the race-based equations (such as the GLIR) for lung function studies should be replaced by race-neutral equations. Based on this, the GLI developed race-neutral equations (GLIN) for spirometry in 2022.
As Rosas-Salazar and his colleagues put it in their paper published in JAMA Pediatrics, “it has been recognized for some time that race is a social construct, many individuals have mixed racial backgrounds, and the relationship of race to genetic ancestry is ambiguous at best.”
“Furthermore, there is evidence that differences in lung function across populations may be driven by sociodemographic, environmental, lifestyle, and other social determinants of health,” they wrote.
The researchers analyzed spirometry tests conducted in 24,630 children and young adults aged 6 to 21 years old between 2013 and 2022 at the Monroe Carell Jr. Children’s Hospital at Vanderbilt and the UPMC Children’s Hospital of Pittsburgh.
When race-neutral equations (GLIN) were applied, the number of tests with a normal lung function pattern decreased by 19.5% among Black children and increased by 7.3% among White children compared to when race-based equations (GLIR) were used.
The change in Black children was largely due to their results being reclassified from “dysanapsis,” a developmental condition characterized by disproportionate growth between lung size and the caliber, or internal diameter, of the airways, to an obstructive pattern, such as that seen in asthma.
The implementation of the new race-neutral equations (GLIN) could change profoundly the diagnosis and management of chronic lung diseases, which are more prevalent in children of under-represented minorities, the researchers concluded.
Applying race-neutrality to spirometry interpretation may prompt additional testing or lead to an “escalation” of asthma care that includes the prescription of inhaled corticosteroids.
“Ultimately,” they continued, “we hope that the use of GLIN will aid in halting racism in health care, increase the attention to modifiable risk factors for reduced lung function in children, and decrease health disparities in the pediatric population.”