Figure 1
From: Plasma YKL-40 and all-cause mortality in patients with chronic obstructive pulmonary disease
Plasma YKL-40 and COPD severity. Boxplots of plasma concentrations of YKL-40 in patients with COPD according to disease severity. Moderate COPD (79–50 FEV1 % predicted), severe COPD (30–50 FEV1 % predicted) and very severe COPD (< 30 FEV1 % predicted). The median score is the line in the middle of the box, and the 25th and 75th percentiles are the lower and upper part of the box. The whiskers are the 5th and 95th percentiles. Outliers are given as dots. No significant differences were found (Kruskal-Wallis test).