Table 5.

Performance and internal validation of all the multivariate cox proportional hazard models

MV model	c-index	95% CI	Mean c-index from 1000 bootstraps	95% CI based on 1000 bootstrap samples	Optimism	Optimism in %
M1	0.7872	0.7648–0.8095	0.7891	0.7678–0.8111	0.0019	0.24%
M2	0.7842	0.7617–0.8066	0.7878	0.7660–0.8103	0.0036	0.46%
M3	0.7817	0.7591–0.8043	0.7840	0.7626–0.8066	0.0023	0.29%
M4	0.7810	0.7588–0.8032	0.7841	0.7638–0.8056	0.0031	0.40%
M5	0.7821	0.7598–0.8043	0.7839	0.7621–0.8072	0.0018	0.23%
M6	0.7791	0.7564–0.8018	0.7715	0.7604–0.8034	−0.0076	−0.96%

MV multivariate, CI confidence interval

M1: the multivariate cox model using QLQ-C30 as continuous variables

M2: the multivariate cox model using QLQ-C30 as dichotomized variables

M3: the multivariate cox model using C30 index score

M4: the multivariate cox model using QLQ-HCC18 as continuous variables

M5: the multivariate cox model using QLQ-HCC18 as dichotomized variables

M6: the multivariate cox model using HCC18 index score