Table 2.

Comparison of aggregation methods.

Model	C-Index (95% CI)
Cox proportional hazards
Unweighted average	0.610 (0.570–0.646)
Weighted average	0.604 (0.571–0.641)
Weighted average of largest 3 metastases	0.627 (0.595–0.661)
Largest + number of metastases	0.612 (0.579–0.649)
Largest metastasis	0.598 (0.559–0.636)
Smallest metastasis	0.595 (0.567–0.631)
Cox proportional hazards with LASSO regression
Unweighted average	0.612 (0.585–0.647)
Weighted average	0.603 (0.573–0.640)
Weighted average of largest 3 metastases	0.628 (0.591–0.666)
Largest + number of metastases	0.597 (0.560–0.632)
Largest metastasis	0.596 (0.562–0.630)
Smallest metastasis	0.597 (0.557–0.630)
Random survival forest
Unweighted average	0.649 (0.548–0.709)
Weighted average	0.641 (0.567–0.729)
Weighted average of largest 3 metastases	0.652 (0.565–0.727)
Largest + Number of metastases	0.622 (0.542–0.706)
Largest metastasis	0.627 (0.544–0.694)
Smallest metastasis	0.621 (0.529–0.709)