Severity of Lung Impairment

Severity

Z Score

Mild

-1.65 to -2.5

Moderate

-2.51 to -4.0

Severe

<-4.1

Data from Stanojevic S, Kaminsky DA, Miller MR, et al. ERS/ATS technical standard on interpretive strategies for routine lung function tests. Eur Respir J 2022;60(1):2101499. Published 2022 Jul 13. doi:10.1183/13993003.01499-2021