Fig. 3

Fig. 3 shows cumulative survival rates during 6 months of AECOPD patients according to (a) readmission duration (< 30 vs > 30 d) and CAP, (b) readmission duration (≤ 30 vs > 30 d) and serum DNI level (< 3.5 vs ≥ 3.5%). a It shows the lowest cumulative survival rate in AECOPD with readmission ≤30 d and CAP (HR 23.549, 95% CI 11.234–49.364, P < 0.001). b It shows also the lowest cumulative survival rate in AECOPD with readmission ≤30 d and serum DNI ≥ 3.5% according to readmission duration and serum DNI level (HR 20.642, 95% CI 10.129–42.067, P < 0.001). AECOPD = acute exacerbation of chronic obstructive pulmonary disease; CAP = community-acquired pneumonia; DNI = delta neutrophil index; d = days