Figure 1. Kaplan-Meier curves showing readmission for acute exacerbation of COPD (AECOPD) during the 12-month follow-up period after the index AECOPD. The curves for readmission are presented for the four subgroups of the patient cohort, categorized on the basis of the patient serum level of high-sensitivity C-reactive protein (hsCRP) at discharge and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) risk category. The order of the groups, ranked from highest to lowest readmission rate (p < 0.001), was as follows: serum hsCRP = 3 mg/L and GOLD category D; serum hsCRP = 3 mg/L and GOLD categories A-C; serum hsCRP < 3 mg/L and GOLD category D; and serum hsCRP < 3 mg/L and GOLD categories A-C.