Spirometry used alone in emphysema can lead to underdiagnosis: Study
Chicago, Illinois: Relying on spirometry alone for emphysema identification in Black adults can lead to underdiagnosis and exacerbate racial disparities, says a study published in Annals of Internal Medicine. The study, secondary data analysis of the CARDIA Lung study, indicates the need for CT imaging for evaluating lung health in this population.
Computed tomography (CT) imaging complements spirometry and may provide an understanding of racial disparities in respiratory health. Considering this, Gabrielle Y. Liu, Northwestern University Feinberg School of Medicine, Chicago, Illinois, and colleagues aimed to determine the difference in the prevalence of emphysema between Black and White adults with different measures of normal spirometry results.
For this purpose, the researchers conducted an observational study using clinical data and spirometry from the CARDIA (Coronary Artery Risk Development in Young Adults) study obtained from 2015 to 2016, and CT scans were done from 2010 to 2011 across 4 U.S. centers.
Self-identified race and visually identified emphysema were measured on CT in participants with different measures of "normal" spirometry results, and calculated using standard race-specific and race-neutral reference equations.
Salient findings of the study include:
- A total of 2674 participants (485 Black men, 762 Black women, 659 White men, and 768 White women) had both a CT scan and spirometry available for analysis.
- Among participants with a race-specific FEV1 between 80% and 99% of predicted, 6.5% had emphysema.
- In this group, emphysema prevalence was 3.9-fold (15.5% vs. 4.0%) higher among Black men than White men and 1.9-fold (6.6% vs. 3.4%) higher among Black women than White women.
- Among participants with a race-specific FEV1 between 100% and 120% of predicted, 4.0% had emphysema. In this category, Black men had a 6.4-fold (13.9% vs. 2.2%) higher prevalence of emphysema than White men, whereas Black and White women had a similar prevalence of emphysema (2.6% and 2.0%, respectively).
- The use of race-neutral equations to identify participants with an FEV1 percent predicted between 80% and 120% attenuated racial differences in emphysema prevalence among men and eliminated racial differences among women.
The researchers wrote, "emphysema is often present before spirometry findings become abnormal, particularly among Black men."
"Relying on spirometry alone for differentiating lung health from lung disease may lead to the underrecognition of impaired respiratory health and exacerbate racial disparities," they concluded.
Reference:
The study titled, "Comparing Racial Differences in Emphysema Prevalence Among Adults With Normal Spirometry: A Secondary Data Analysis of the CARDIA Lung Study," was published in Annals of Internal Medicine.
DOI: https://doi.org/10.7326/M22-0205
