Table 3.

C-statistics and 95% confidence intervals (CI) for fivefold cross-validated Cox proportional hazard models built from harmonized data, and log-rank p-values for Kaplan–Meier curve separation. ComBat (CE) indicates data was harmonized by contrast enhancement with ComBat.

	5fold CV c-statistic	95% CI	Log-rank p-value
Lung3/CAPTK
Original	0.59	[0.53, 0.65]	0.0004
ComBat (CE)	0.60	[0.54, 0.64]	0.0029
Nested	0.63	[0.59, 0.67]	0.0025
NestedD	0.63	[0.58, 0.68]	0.0058
GMM	0.50	[0.42, 0.56]	0.011
GMM + ComBat (CE)	0.50	[0.42, 0.56]	0.036
Lung3/PyRadiomics
Original	0.62	[0.57, 0.66]	0.061
ComBat (CE)	0.61	[0.57, 0.66]	0.029
Nested	0.62	[0.56, 0.67]	0.022
NestedD	0.64	[0.58, 0.69]	0.0062
GMM	0.59	[0.53, 0.65]	0.01
GMM + ComBat (CE)	0.58	[0.52, 0.63]	0.016
Radiogenomics/CAPTK
Original	0.55	[0.52,0.63]	0.071
ComBat (CE)	0.55	[0.50,0.59]	0.056
Nested	0.56	[0.52,0.63]	0.016
NestedD	0.54	[0.53,0.65]	0.074
GMM	0.56	[0.51,0.64]	0.02
GMM + ComBat (CE)	0.58	[0.53,0.64]	0.071
Radiogenomics/PyRadiomics
Original	0.57	[0.52,0.63]	0.17
ComBat (CE)	0.63	[0.53,0.67]	0.0003
Nested	0.62	[0.53,0.69]	0.004
NestedD	0.61	[0.53,0.68]	0.0078
GMM	0.61	[0.51,0.66]	0.0012
GMM + ComBat (CE)	0.63	[0.52,0.68]	0.0002