Table 4.

Comparison of different esophageal cancer risk prediction models

Model comparison	Difference of AUC	Za	P valuea	NRI	Zb	P valueb
Training set
Genetic vs. non-genetic	0.032(-0.028,0.091)	1.034	0.301	0.041	0.755	0.450
Genetic vs. combined	0.089(0.048,0.130)	4.256	< 0.001	0.122	3.234	0.001
Non-genetic vs. combined	0.058(0.030,0.086)	4.067	< 0.001	0.082	2.082	0.037
Validation set
Genetic vs. non-genetic	0.004(-0.072,0.079)	0.091	0.927	-0.002	0.020	0.984
Genetic vs. combined	0.060(0.007,0.113)	2.223	0.026	0.075	1.214	0.225
Non-genetic vs. combined	0.057(0.021,0.092)	3.084	0.002	0.076	2.128	0.033

NOTE: The difference of AUC was analyzed using Delong’s test. NRI, net reclassification improvement.

^a represents the z-statistic and P value from Delong’s test;

^b represents the z-statistic and P value from NRI analysis