Table 3:

Multivariate Analysis of Factors Associated with Influenza-Related Neurologic Complications

	Adjusted OR	95% Confidence Interval	p-value
A: Among the entire cohort (n=1,217)
Presence of a pre-existing neurologic diagnosis	4.6	3.2-6.7	<0.001
No annual influenza vaccinea	1.6	1.1-2.3	0.020
Age ≤5 years oldb	1.6	1.1-2.3	0.017
Influenza strain Bc	1.4	0.9-2.0	0.10
B: Among children without pre-existing neurologic diagnosis (PND; n=326)
No annual influenza vaccine	2.1	1.2-3.7	0.013
Age ≤5 years old	3.1	1.7-5.7	<0.001
Influenza strain B	0.8	0.5-1.6	0.60
C: Among children with pre-existing neurologic diagnosis (PND; n=891)
No annual influenza vaccine	1.3	0.7-2.1	0.39
Age ≤5 years old	0.9	0.5-1.6	0.75
Influenza strain B	2.0	1.2-3.4	0.012

Effect modification of the presence of a pre-existing neurologic diagnosis was examined a priori:

^ap=0.27

^bp=0.002

^cp=0.017