Table III.

Comparison of median LOS (in days) with interquartile range (IQR) for all infants and for infants who had an EV PCR test obtained

All Infants
	CSF EV PCR Not Tested N=15,509	CSF EV PCR Tested N=4,444	Median Difference (95% CI)	Incident Rate Ratioa (95% CI)
All infants (n=19,953)	2.4 (2.0, 3.3)	2.3 (1.9, 3.1)	0.1 (0.1, 0.2)	0.97 (0.89, 1.06)
0–28 days of age (n=11,054)	2.5 (2.0, 3.7)	2.4 (2.0, 3.6)	0.1 (0.0, 0.1)	1.05 (0.93, 1.19)
29–60 days of age (n=8,899)	2.3 (1.9, 3.0)	2.2 (1.8, 2.9)	0.1 (0.1, 0.2)	0.87 (0.80, 0.94)
CSF pleocytosisb (n=4,087)	2.4 (2.0, 3.4)	2.2 (1.8, 3.0)	0.2 (0.1, 0.3)	0.89 (0.78, 1.02)
Infants who had an EV PCR test obtained
	CSF EV PCR Negative N=3,499	CSF EV PCR Positive N=945	Median Difference (95% CI)	Incident Rate Ratioa (95% CI)
All infants (n=4,444)	2.4 (1.9, 3.6)	2.0 (1.6, 2.6)	0.4 (0.3, 0.5)	0.62 (0.57, 0.68)
0–28 days of age (n=2,450)	2.5 (2.0, 3.9)	2.1 (1.8, 2.8)	0.4 (0.2, 0.5)	0.65 (0.57, 0.74)
29–60 days of age (n=1,994)	2.3 (1.9, 3.1)	1.9 (1.3, 2.4)	0.4 (0.3, 0.5)	0.59 (0.52, 0.68)
CSF pleocytosisb (n=1,163)	2.5 (2.0, 3.8)	2.0 (1.6, 2.6)	0.5 (0.4, 0.7)	0.56 (0.48, 0.64)

^aAdjusted for patient age and study year, and clustered by hospital center

^bCSF WBC ≥ 20 cells/mm³ for infants 0 to 28 days of age and CSF WBC ≥ 10 cells/mm³ for infants 29 to 60 days of age

CSF: cerebrospinal fluid; EV: Enterovirus; LOS: length of stay; PCR: polymerase chain reaction