Figure 2. Association of Race-Neutral Reference Equations With Forced Expiratory Volume in First Second of Expiration (FEV₁), Forced Vital Capacity (FVC), and Percent FVC Exhaled in the First Second (FEV₁/FVC) z Scores in Black and White Individuals.

Differences in the z scores of FEV₁ (A), FVC (B), and FEV₁/FVC (C) among Black and White individuals when applying the race-specific 2012 Global Lung Function Initiative reference equations and the race-neutral Global Lung Function Initiative Global reference equations. An increase in z score represents an increase in apparent pulmonary function, while a decrease represents a decline in apparent pulmonary function.