Table 1. Accuracy of the BD Directigen Flu A+B test and the BD Directigen EZ Flu A+B test during different influenza seasons calculated using the RT-PCR (A+B) assay as a gold standard.

	PCR negative	PCR positive	Sensitivity % (95%CI)	Specificity % (95% CI)	PPV % (95% CI)	NPV % (95% CI)
BD Directigen Flu A+B (RT)
2003–2004
negative	172	23	49 (34–64)	100 (97–100)	100 (81–100)	88 (82–92)
positive	0	22
n = 217	172	45
2006–2007
negative	212	155	40 (34–46)	99 (97–99)	99 (94–99)	57 (52–62)
positive	1	105
n = 473	213	260
2007–2008
negative	126	222	38 (33–43)	97 (92–99)	97 (92–99)	36 (31–41)
positive	4	136
n = 488	130	358
2008–2009
negative	231	166	36 (30–42)	99 (96–99)	97 (91–99)	58 (53–63)
positive	2	94
n = 493	233	260
Total
negative	741	566	39 (35–42)	99 (97–99)	98 (95–99)	56 (53–59)
positive	7	357
n = 1671	748	923
BD Directigen EZ Flu A+B (RT)
2010–2011
negative	56	42	51 (40–62)	100 (92–100)	100 (90–100)	57 (47–67)
positive	0	45
n = 143	56	87
2011–2012
negative	57	37	41 (29–54)	100 (92–100)	100 (83–100)	60 (49–70)
positive	0	26
n = 120	57	63
2012–2013
negative	87	83	47 (39–55)	98 (91–99)	98 (91–99)	51 (43–58)
n positive	1	74
n = 245	88	157
Total
negative	200	162	47 (41–53)	100 (97–100)	99 (95–99)	55 (50–60)
positive	1	145
n = 508	201	307

Key: CI—confidence interval

PPV—positive predictive value

NPV—negative predictive value