. 2021 Jun 28;11:682271. doi: 10.3389/fonc.2021.682271

Table 3.

The C-index of nomograms for OS and PFS in the training set and validation set.

Model for survival prediction	The training set		The validation set
Model for survival prediction	C-index	95%CI	C-index	95%CI
OS nomogram	0.755	0.704–0.807	0.673	0.551–0.796
TNM classification(OS)^a	0.694	0.638–0.749	0.591	0.463–0.720
PFS nomogram	0.698	0.652–0.744	0.638	0.538–0.738
TNM classification(PFS)^b	0.662	0.614–0.710	0.596	0.508–0.684

^aTNM classification (OS), OS nomogram based on TNM classification; ^bTNM classification (PFS), PFS nomogram based on TNM classification. C-index, concordance index; OS, overall survival; PFS, progression-free survival; CI, confidence interval.