The step from a voluntary to a mandatory national nosocomial infection surveillance system: the influence on infection rates and surveillance effect

Table 1 Characteristics of NICU surveillance data in 26 old/voluntary and 95 new/mandatory participants in NEO-KISS, year 2007

Parameter	Old/voluntary participants (N = 26, starting in NEO-KISS 1January 2000- December 2002)	New/mandatory participants (N = 95, starting in NEO-KISS January-December 2006)	p-value^a
NICU characteristics
Number of beds in the NICU, median	24	16	0.004
Number of VLBW infants year 2007, median	53	23	<0.001
Months of participation until December 2010, median	123	56	<0.001
Number VLBW infants	1527	2753
Birth weight (gram), mean	1100	1140	0.001
End of surveillance
Transfer before 1800 g	21.4%	13.10%
End of surveillance 1800 g	71.9%	80.0%
Died	6.7%	7.0%
Number VLBW infants according to birth weight groups (%)
< 500 g	52 (3.4%)	92 (3.3%)
1000-1499 g	615 (40.3%)	1012 (36.8%)
1000-1499 g	860 (56.3%)	1649 (59.9%)
Device utilization rates per 100 patient days (pooled mean)#
CVC
500-999 g	28.2	30.2	0.484
1000-1499 g	13.8	16.9	0.934
Tube
500-999 g	21.2	21.2	0.267
1000-1499 g	6.3	6.1	0.676
Healthcare associated infection rates per 1000 patient days (pooled mean)#
Primary BSI
500-999 g	6.5	5.2	0.023
1000-1499 g	3.1	3.2	0.964
Pneumonia
500-999 g	1.0	0.8	0.286
1000-1499 g	0.4	0.1	0.053
Device-associated infection rates per 1000 device days (pooled mean)#
CVC-BSI
500-999 g	11.4	9.4	0.011
1000-1499 g	7.7	6.9	0.150
Tube associated pneumonia
500-999 g	2.2	2.3	0.634
1000-1499 g	3.9	0.4	0.010

NICU, neonatal intensive care unit; BSI, bloodstream infection; CVC-BSI, Central venous catheter-associated bloodstream infection; VLBW, very low birth weight; # Data for the birth weight group < 500 g are not shown because of the small number of VLBW infants in this group; ^a p-value, Wilcoxon test; ^b p-value, Chi square test.