Validity and timeliness of syndromic influenza surveillance during the autumn/winter wave of A (H1N1) influenza 2009: results of emergency medical dispatch, ambulance and emergency department data from three European regions

Table 6 Sensitivity, specificity, and false detection rate of Poisson CUSUM signals for syndromic influenza surveillance during week 36 (30.8.) to week 52 (31.12.) in 2009

Data source	Sensitivity*%	Specificity^†%	Sensitivity*%	Specificity^†%	False detection rate^‡%
	Weekly		Daily		Weekly	Daily
EMD-AT	(3/9)	(5/8)	(5/67)	(53/56)	(3/6)	(3/8)
EMD-AT	33.3	62.5	7.5	94.6	50.0	37.5
EP-AT	(0/9)	(8/8)	(0/67)	(56/56)	(0/0)	(0/0)
EP-AT	0.0	100.0	0.0	100.0
EP-BE	(6/10)	(6/7)	(12/70)	(51/53)	(1/7)	(2/14)
EP-BE	60.0	85.7	17.1	96.2	14.3	14.3
ED-BE	(10/10)	(4/7)	(26/70)	(45/53)	(3/13)	(8/34)
ED-BE	100.0	57.1	37.1	84.9	23.1	23.5
ED-ES	(6/8)	(8/9)	(30/56)	(63/67)	(1/7)	(4/34)
	75.0	88.9	53.6	94.0	14.3	11.8

*Brackets: Number of weeks / days with at least one true-positive Poisson CUSUM signal in syndromic surveillance data divided by number of pandemic weeks/days according to reference data.
^†Brackets: Number of true-negative weeks / days (no Poisson CUSUM signal) in syndromic surveillance data divided by number of weeks / days outside the pandemic period according to reference data.
^‡Brackets: Number of weeks/days with a false-positive Poisson CUSUM signal in syndromic surveillance data divided by all Poisson CUSUM signals of syndromic surveillance data.

ISSN: 1471-2458