Fig. 2

In the derivation cohort, patients with RDW ≥ 14.1% had significantly lower median FVC%pred than patients with RDW < 14.1% [75.5, (95% CI 71.2–79.2) vs. 78.3, (95% CI 76.0–81.0), (P = 0.04)] (a). Patients with baseline RDW ≥ 14.1% had significantly lower median FVC%pred [69.4, (95% CI 65.5–76.4)] compared to patients with baseline RDW < 14.1% [80.8, (95% CI 76.0–83.3)] in the validation cohort, (P = 0.001), (b). In the derivation cohort, patients with RDW ≥ 14.1% had significantly lower median DLCO%pred than patients with RDW < 14.1% [45.4, (95% CI 43.3–50.5) vs. 53.0, (95% CI 50.8–56.8), (P = 0.008)] (c). Median DLCO%pred was also lower for patients with baseline RDW ≥ 14.1% [37.9, (95% CI 33.4–40.7)] compared to patients with baseline RDW < 14.1% [44.4, (95% CI 41.5–48.9)] in the validation cohort, (P < 0.001), (d)