Table 3. Threshold normalized G6PD activity values on the CareStart biosensor optimized to maximize sensitivity and specificity using Youden’s Index.

30% Threshold on Gold Standard assay (2.37 IU/g Hb)
Optimal Threshold G6PD activity (IU/g Hb)	4.55
Sensitivity at Threshold (95%CI)	1.00 (0.89–1.00)
Specificity at Threshold (95%CI)	0.92 (0.86–0.97)
Youden’s Index	0.92
40% Threshold on Gold Standard assay (3.16 IU/g Hb)
Optimal Threshold G6PD activity (IU/g Hb)	4.55
Sensitivity at Threshold (95%CI)	0.96 (0.83–1.00)
Specificity at Threshold (95%CI)	0.97 (0.91–0.99)
Youden’s Index	0.93
70% Threshold on Gold Standard assay (5.54 IU/g Hb)
Optimal Threshold G6PD activity (IU/g Hb)	5.15
Sensitivity at Threshold (95%CI)	0.79 (0.67–0.86)
Specificity at Threshold (95%CI)	0.98 (0.92–1.00)
Youden’s Index	0.77
80% Threshold on Gold Standard assay (6.33 IU/g Hb)
Optimal Threshold G6PD activity (IU/g Hb)	6.1
Sensitivity at Threshold (95%CI)	0.92 (0.85–0.97)
Specificity at Threshold (95%CI)	0.94 (0.83–0.99)
Youden’s Index	0.86