Current diagnostic tools fail to diagnose COPD in African-Americans
A recent study Journal of General Internal Medicine sheds light on a significant disparity in the diagnosis of Chronic Obstructive Pulmonary Disease (COPD) among African-American individuals, prompting the need for broader diagnostic criteria to ensure accurate identification of the disease across diverse populations. The research, conducted by the Genetic Epidemiology of COPD (COPDGene) study, highlights that the conventional fixed-ratio spirometry criteria may lead to underdiagnosis of COPD in African-Americans compared to their non-Hispanic white counterparts.
The COPDGene study, a multicenter, longitudinal cohort study in the United States, analyzed data spanning from 2007 to the present. It specifically focused on COPD diagnosis, manifestations, and outcomes, with a keen eye on racial disparities. The research included both non-Hispanic white (NHW) and African-American (AA) participants, with a substantial sample size.
Using the fixed-ratio spirometry criteria of FEV1/FVC < 0.7, the study found that 70% of African-American participants (n = 3366) were classified as non-COPD, while only 49% of non-Hispanic white participants (n = 6766) were classified as such. This stark difference raised concerns about the accuracy of COPD diagnosis in African-Americans. Further investigation revealed that African-American smokers had a younger age of diagnosis, higher current smoking rates (80% vs. 39%), and fewer pack-years, yet exhibited similar 12-year mortality rates compared to their non-Hispanic white counterparts.
The study delved deeper into the spirometry data, demonstrating disproportionate reductions in Forced Vital Capacity (FVC) relative to Forced Expiratory Volume in one second (FEV1) in African-American participants. This skewed reduction pattern led to higher FEV1/FVC ratios, potentially contributing to the underdiagnosis of COPD in this population.
Additionally, they revealed that African-American individuals classified as GOLD 0 (FEV1 ≥ 80% predicted and FEV1/FVC ≥ 0.7) exhibited greater respiratory symptoms, worse DLCO (diffusing capacity of the lungs for carbon monoxide), spirometry results, and BODE scores compared to matched non-Hispanic white participants.
Interestingly, the study identified a correlation between the disproportionate reductions in FVC and higher deprivation levels among African-American participants, suggesting a potential link between socioeconomic factors and COPD manifestations.
Source:
Regan, E. A., Lowe, M. E., Make, B. J., Curtis, J. L., Chen, Q., Cho, M. H., Crooks, J. L., Lowe, K. E., Wilson, C., O’Brien, J. K., Baldomero, A. K., Bhatt, S. P., McCormack, M. C., Hansel, N. N., Kim, V., … Wise, R. (2023). Use of the Spirometric “Fixed-Ratio” Underdiagnoses COPD in African-Americans in a Longitudinal Cohort Study. In Journal of General Internal Medicine. Springer Science and Business Media LLC. https://doi.org/10.1007/s11606-023-08185-5
