Table 3.

NRI and IDI of the nomogram and the TNM stage in survival prediction for SCLC patients in the training and validation sets

Index	Training set				Validation set
	Estimate	95%CI	p		Estimate	95%CI	p
NRI (vs. the TNM stage)
1-year OS	0.255	0.189–0.308	< 0.001		0.154	0.034–0.257	0.012
3-year OS	0.210	0.143–0.274	< 0.001		0.157	-0.030-0.271	0.096
5-year OS	0.198	0.106–0.274	< 0.001		-0.040	-0.226-0.106	0.363
IDI (vs. the TNM stage)
1-year OS	0.056	0.040–0.080	< 0.001		0.040	0.014–0.065	0.004
3-year OS	0.047	0.032–0.071	< 0.001		0.025	-0.010-0.052	0.112
5-year OS	0.041	0.024–0.067	< 0.001		-0.006	-0.064-0.031	0.715

Note: NRI, Net Reclassification Improvement; IDI, Integrated Discrimination Improvement; OS, overall survival