Fig. 2

Exposure–response associations for NHHR and PRISm derived by restricted cubic spline modeling (weighted). A A linear association exists between NHHR and PRISm. B A linear association exists between FEV1 and PRISm. C A linear association exists between FVC and PRISm. D A non-linear association exists between NHHR and FEV1/FVC. E A non-linear association exists between NHHR and FEV1%