TABLE 3.

Performance of Directigen Flu A + B membrane immunoassay rapid test compared to that of viral culture when analyzed by age group (younger than 2 years old and older or equal to 2 years) for detection of influenza A and B viruses

Age and virus type detected by rapid test	Sensitivity (%)	Specificity (%)	% of specimens with indicated PVa
			Pos	Neg
A and B
<2 yrs	50.0	99.9	93.1	98.7
≥2 yrs	35.3*b	99.4	83.3*	94.8*
A only
<2 yrs	45.7	99.9	88.9	99.1
≥2 yrs	34.4*	99.7	78.6*	98.1
B only
<2 yrs	57.9	100.0	100.0	99.6
≥2 yrs	35.8*	99.7	86.4*	96.8*

^aPV, predictive value; Pos, positive; Neg, negative.

^b*, P value of <0.001.