Table 3. Prognostication comparison of built-up nomogram and original Leibovich model.

		C-index (95%CI)				AIC
Patients group	No. of patients (%)	Nomogram	Leibovich	Coefficient (95%CI)	P	Nomogram	Leibovich
Overall	472 (100%)	0.854 (0.811 to 0.896)	0.836 (0.790 to 0.882)	0.037 (0.013 to 0.061)	0.010	706.0	738.2
TNM stage I+II	345 (73.1%)	0.819 (0.750 to 0.888)	0.768 (0.696 to 0.839)	0.051 (0.001 to 0.101)	0.044	404.8	410.0
UISS low or intermediate risk	438 (92.8%)	0.847 (0.790 to 0.903)	0.797 (0.738 to 0.856)	0.048 (0.015 to 0.082)	0.005	559.7	593.9
SSIGN low or intermediate risk	458 (97.0%)	0.848 (0.796 to 0.900)	0.801 (0.746 to 0.856)	0.049 (0.018 to 0.079)	0.002	608.5	645.0

Abbreviation: C-index, concordance index; AIC, Akaike's information criterion; UISS, UCLA Integrated Staging System; SSIGN, Mayo clinic stage, size, grade, and necrosis; 95% CI, 95% confidence interval.

C-index, 95%CI and AIC are calculated from 1000 bootstrap samples to protect from overfitting.