Table 2. Performance (AUC) for selected groups of features with small and large ROI.

AUC	50k pixel ROI		100k pixel ROI
Feature group	PaO2/FiO2	A-a gradient	PaO2/FiO2	A-a gradient
1	0.575	0.614	0.724	0.586
2	0.647	0.652	0.710	0.538
3	0.663	0.538	0.626	0.695
All	0.716	0.552	0.718	0.652