Development and validation of novel nomograms to predict survival of patients with tongue squamous cell carcinoma

Table 4 Net reclassification index and concordance index values of the nomograms and tumor-node-metastasis staging system, reflecting the predictive accuracy for overall and cancer-specific survival in tongue squamous cell carcinoma patients

Index	Training cohort		Validation cohort
	Estimate	95%CI	Estimate	95%CI
NRI (vs TNM stage)
For 3-year OS	0.493	(0.418, 0.589)	0.635	(0.228, 1.096)
For 5-year OS	0.482	(0.413, 0.613)	0.750	(0.397, 1.240)
For 3-year CSS	0.424	(0.354, 0.523)	0.354	(0.145, 1.037)
For 5-year CSS	0.402	(0.345, 0.536)	0.608	(0.180, 1.186)
C-index
The nomogram OS	0.741	(0.725, 0.756)	0.800	(0.747, 0.853)
The nomogram CSS	0.757	(0.739, 0.775)	0.830	(0.779, 0.881)
TNM stage OS	0.643	(0.636, 0.668)	0.695	(0.617, 0.750)
TNM stage CSS	0.678	(0.660, 0.696)	0.749	(0.673, 0.825)

CI: Confidence interval; NRI: Net reclassification index; C-index: Concordance index; OS: Overall survival; CSS: Cancer-specific survival; TNM: Tumor-node-metastasis.