Table 3

C-index of the models at 1 month, 6 months and 12 months in derivation, internal validation and external validation set

1 month6 months12 months
Severe exacerbation
 Derivation set77.3 (70.7, 83.9)76.5 (72.6, 80.4)74.7 (71.2, 78.2)
 Internal validation set77.6 (59.9, 95.3)74.6 (62.3, 86.9)72.3 (61.2, 83.5)
 External validation set64.5 (57.2, 71.8)63.5 (58.9, 68.1)64.3 (60.0, 68.5)
COPD-specific readmission
 Derivation set77.1 (70.1, 84.0)76.3 (72.3, 80.4)74.5 (71.0, 78.0)
 Internal validation set81.1 (66.1, 96.2)73.4 (59.5, 87.3)72.0 (60.3, 83.7)
 External validation set63.8 (56.4, 71.2)63.1 (58.5, 67.8)64.1 (59.9, 68.4)
  • COPD, chronic obstructive pulmonary disease.