Impact of Spirometry Race-Correction on Preadolescent Black and White Children

To evaluate the impact of race-correction in spirometry testing among Black and white children and assess the frequency of asthma symptoms in Black children who were differentially classified depending on whether race-corrected or race-uncorrected reference equations were used.The study included 454 children from Detroit, Michigan who were enrolled in the Wayne County Health, Environment, and Allergy and Asthma Longitudinal Study birth cohort.Participants were invited for a clinic visit at age 10 years that included history, physical exam, and spirometry. The analysis only included children who identified as Black, non-Hispanic, non-Arabic and white, non-Hispanic, non-Arabic children. Race was obtained by parental report at the study’s 2-year clinic visit. Because of small sample size, other race and multiracial children were excluded in the analysis. Three different 2012 Global Lung Initiative reference equations were applied to spirometry: (1) race-corrected (Black children assigned “African American” and white children assigned “Caucasian”), (2) race-uncorrected (all participants assigned to the population averaged race composite category of “other or mixed”), and (3) all children assigned as “Caucasian.” Abnormal spirometry values were defined as % predicted values <5% in forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio. The International Study of Asthma and Allergies in Childhood questionnaire was used to assess frequency of asthma symptoms, and the Asthma Control Test was used to assess asthma control. Standard statistical analysis and linear regression were used to determine associations between spirometry classification and race.The study included 343 Black children and 111 White children from the WHEALS cohort, and there were no significant differences in age at spirometry testing, height, or sex between the groups. Black children were more likely to report asthma symptoms in the past 12 months and have lower ACT scores, indicating less asthma control. Race-corrected spirometry identified 24 Black children with abnormal FEV1, but an additional 38 Black children were classified as having abnormal FEV1 when using race-uncorrected equations. Similarly, for FEV1/FVC, race-uncorrected equations classified 16 Black children as abnormal in addition to the 68 Black patients identified on race-corrected equations. Over half of Black patients (52.6%) classified as normal on race-corrected spirometry and abnormal on race-uncorrected spirometry reported asthma symptoms in the past 12 months. Race-uncorrected spirometry did not identify any additional white children with abnormal spirometry that were not already classified as abnormal using race-corrected equations.Race-correction had extensive impact on spirometry classification in Black children and the use of race-correction in spirometry should be re-evaluated.Race-correction in spirometry is based on historical assumptions of biological differences and has important implications for the interpretation of spirometry results. Race-correction in spirometry assumes reduced lung function at baseline in Black patients and is associated with the underestimation of abnormal results. This affects clinical care and may also impact Black patients with regards to organ transplantation or clinical trial eligibility. As race is increasingly considered a flawed biologic marker in medicine that contributes to unequal care, race-neutral spirometry is recommended.