Classification scheme used to assess lung function in a cohort of adult African-American participants in the CSSCD. (Modified from Pellegrino et al,²³  Hyatt el al,²⁴  and Iyer et al.²⁵ ) *The nonspecific pattern was defined based on Hyatt el al²⁴  and Iyer et al²⁵ : FVC% predicted <LLN with FEV₁/FVC% predicted ≥LLN and TLC% predicted ≥80%.