TABLE II.

Sensitivity and Specificity for the Detection of HbA, HbS, and HbC

		Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)
HbA	Observer 1	99.0	92.3	97.1	97.3
	Observer 2	97.0	94.9	98.0	92.5
	Observer 3	99.0	94.9	98.0	97.4
	Cumulative:	98.3	94.0	97.7	95.7
	(95% Cl)	(96.2–99.5)	(88.1–97.6)	(95.3–99.1)	(90.1–98.6)
HbS	Observer 1	100	92.4	93.6	100
	Observer 2	98.6	92.4	93.5	98.4
	Observer 3	100	92.5	93.5	100
	Cumulative:	99.5	92.5	93.5	99.5
	(95% Cl)	(97.5–100)	(87.9–95.7)	(89.6–96.3)	(97.0–100)
HbC	Observer 1	100	100	100	100
	Observer 2	100	100	100	100
	Observer 3	100	100	100	100
	Cumulative:	100	100	100	100
	(95% Cl)	(92.1–100)	(99.0–100)	(92.1–100)	(99–100)