S2.

Performance of CART model on data subsets from same time periods

Variables	Data subset (years 2010−2014)	Whole data
CART, classification and regression trees; AUC, the area under receiver operating characteristic curve; 95% CI, 95% confidence interval; *, sensitivity at the 99.0% specificity.
AUC (95% CI)
Training	0.89 (0.88−0.91)	0.90 (0.88−0.91)
Test	0.89 (0.88−0.91)	0.88 (0.87−0.90)
Sensitivity (95% CI)*
Training	66.0% (62.4%−69.5%)	67.0% (63.7%−70.2%)
Test	62.8% (58.3%−67.3%)	62.2% (58.1%−66.2%)