Table 3. Cross-predictability of the BRT models trained with the different epidemic waves of influenza A(H7N9), China, applied to the others, as measured by the area under the curve*.

Predictions	Applied to
	Wave 1	Wave 2	Wave 3	Wave 4	Wave 5
Wave 1	0.91	0.81	0.78	0.84	0.79
Wave 2	NA	0.85	0.78	0.83	0.76
Wave 3	NA	NA	0.82	0.82	0.74
Wave 4	NA	NA	NA	0.83	0.75
Wave 5	NA	NA	NA	NA	0.76

*BRT, boosted regression tree; NA, not applicable.