Fig. 5

Plasma C4Ma3 (a) and plasma fibrinogen (b) levels in COPD subjects with no hospitalizations (n = 839), one hospitalization (n = 81) and more than 2 hospitalizations (n = 28) in the year prior to study start. Data are shown as Tukey box-and-whiskers plot with a line indicating median, the box indicating the IQR) and whiskers indicating 1.5 times the IQR. Asterisks indicate statistical significance: *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001