Table 5.

Internal and external validation of Model 1

	Internal validation: model performance			External validation: model performance
Measure	Original value	Optimism	Corrected	Original value	Optimism	Corrected
C-statistic	0.766	0.018	0.748	0.845	0.052	0.793
R 2	0.277	0.037	0.240	0.458	0.147	0.311
Brier score	0.192	−0.009	0.201	0.155	−0.035	0.190
Slope	1.000	0.090	0.910	1.000	0.328	0.672