Race-Based Spirometry Stymies Asthma Diagnosis in Kids

SAN DIEGO — Several studies presented here at the American Academy of Allergy, Asthma, & Immunology (AAAAI)/World Allergy Organization 2025 Annual Meeting solidify the case that race-neutral spirometry reclassifies some Black children whose poor lung function was masked by race-specific calculations, and furthermore show that these changes have implications for asthma diagnosis and treatment.

Historically, physicians have diagnosed asthma from lung measures derived using reference equations that adjust for age, sex, height — and race, based on the flawed presumption that racial groups have innate differences in lung function. Amid growing recognition of race as a social construct lacking biological basis, in 2023, the American Thoracic Society recommended replacing race-specific with race-neutral equations.

Research has shown that race-specific calculations conceal respiratory impairments disproportionately in Black patients, including children. Several teams have now examined the impact of race on children’s lung function measurements and subsequent asthma diagnosis.

One team, led by first author Wan Chi Chang, MS, a biostatistician at Cincinnati Children’s Hospital Medical Center in Ohio, analyzed more than 1500 children from three cohorts: Childhood Asthma Management Program, Cincinnati Childhood Allergy and Air Pollution, and the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children.

In all three cohorts, “when you use the race-neutral equation, you are picking up twice or even four times more asthmatic children compared to using race-specific equations — mostly in Black children,” Chang said, noting that changes were minimal for White study participants. If anything, their analyses found slightly fewer White children with reduced lung function when using race-neutral assessments.

Compared to the race-neutral equation, the race-specific equation failed to detect reduced lung function in 39% of Black children and made them ineligible for reversibility testing after using a medication.

These findings were presented on March 1 on an AAAAI poster and published the day before in JAMA Network Open.

Another team analyzed more than 8719 children from the nationwide ECHO cohort

and published broadly similar conclusions in the March issue of the American Journal of Respiratory and Critical Care Medicine. In addition, their analysis found, unexpectedly, that for any given level of lung function (FEV₁ or FEV₁/FVC), Black children were more likely to be diagnosed with asthma and more likely to be hospitalized with asthma.

“We expected Black children to be at increased risk for asthma, but I thought that this would be mostly due to Black children having reduced lung function,” said James Gern, MD, professor of pediatrics and medicine at the University of Wisconsin School of Medicine and Public Health in Madison, and senior author of the ECHO analysis. “That was not the case.” 

Higher rates of asthma for Black vs White children with similar lung function could be due to adverse living environments such as more pollution or nutritional deficits, Gern told Medscape Medical News. “The reasons are speculative and need to be verified.”

At a March 1 oral abstract session, Lina Mahmood, MD, an allergy/immunology fellow at the University of Arkansas for Medical Sciences, presented her team’s analysis of race-specific and race-neutral spirometry in 7138 Black, Latino, and White children in Arkansas, a predominantly rural state.

Using race-neutral equations, lung function measurements (ppFEV₁) dropped notably for Black (–11.3%) and less markedly for Latino (–4.3%) children while increasing slightly (+3.1%) for White children. Similar patterns emerged with FEV₁ and FVC z-scores. In all comparisons, Black study participants “were most significantly affected, and their lung function tended to decrease after race-neutral calculations,” Mahmood reported at AAAAI.

These changes in lung function calculations had implications for asthma severity classification. In Black children, cases classified as “moderate” asthma more than doubled (11% to 27%) and “severe” cases nearly tripled (1.6% to 4.5%). Changes were minimal for Latino children, and in older White children over 12 years of age, moderate cases dropped (10.0% to 5.6%), while mild cases increased (88.5% to 93.3%).

All told, race-neutral calculations could reveal more cases of underdiagnosed asthma in Black children, and somewhat less so in Latino children as well, Mahmood said. “And that can provide more opportunities for accurate therapeutic management and early identification of severe asthma, which may contribute to alleviate disparate asthma outcomes.”

Therapeutic management was the focus of another AAAAI poster addressing the impact of race-based spirometry in 2076 children enrolled in Inner-City Asthma Consortium studies between 2002 and 2015. The key question: “If we had used these race-neutral equations back in the day, how many kids would have been put on a higher step of medication because their FEV₁ would show up as being lower?” said Cynthia Visness, MPH, PhD, an epidemiologist at Rho, Inc., a contract research organization that coordinates National Institute of Allergy and Infectious Diseases (NIAID) asthma and allergy research.

Her team’s analysis suggests that 18% of the Black cohort was undertreated. In other words, among Black children who weren’t already at the highest treatment step, 18% would have assigned a higher medication step if asthma control had been assessed with race-neutral equations.

All studies were funded by National Institutes of Health or NIAID. Presenters reported no relevant financial relationships.

Esther Landhuis is a freelance science & health journalist in the San Francisco Bay Area. She can be found on X @elandhuis.