TABLE 2.

Diagnostic performance of the deep learning system

	Training	Validation 1	Validation 2	Validation 2-viral#
Subjects n	709	226	161	121
AUC 95% CI	0.90 (0.89–0.91)	0.87 (0.86–0.89)	0.88 (0.86–0.90)	0.86 (0.83–0.89)
Accuracy %	81.24	78.32	80.12	85.00
Sensitivity %	78.93	80.39	79.35	79.35
Specificity %	89.93	76.61	81.16	71.43
F1-score	86.92	77.00	82.02	90.11

AUC: area under the receiver operating characteristic curve. ^#: a stratified analysis using the patients with coronavirus 2019 and viral pneumonia in validation set 2.