Table 2. Algorithm Performance Metrics.

Model	AUROC	Accuracy, %	F1 score, %	Sensitivity, %	Specificity, %	PPV, %	NPV, %
Teacher
Messidor-2 internal validation 1	0.939	92.0	84.1	80.4	96.1	88.1	93.2
EyePACS internal validation 2	0.886	84.3	51.1	56.1	89.2	46.9	92.2
Egypt external validation	0.964	93.3	96.4	94.4	75.0	98.4	45.0
Student
Messidor-2 internal validation 1	0.951	93.7	87.6	84.8	96.9	90.7	94.7
EyePACS internal validation 2	0.916	74.4	52.0	95.1	70.8	35.8	98.8
Egypt external validation	0.950	96.7	98.3	100	41.7	96.6	100
Bespoke
Messidor-2 internal validation 1	0.985	96.5	94.8	96.5	96.9	89.1	96.1
EyePACS internal validation 2	0.853	74.4	83.2	74.2	75.6	94.7	33.3
Egypt external validation	0.890	94.3	50.0	50.0	97.0	50.0	97.0

Abbreviations: AUROC, area under the receiver operating characteristic curve; NPV, negative predictive value; PPV, positive predictive value.