Cost effectiveness analysis of Year 2 of an elementary school-located influenza vaccination program–Results from a randomized controlled trial

Table 1 Vaccination rates in school-located seasonal influenza vaccination (SLV-I) schools and control schools during Year 1 (2009–2010 season) and Year 2 (2010–2011 season)

	Year 1 (2009–2010)^a					Year 2 (2010–2011)
	SLV-I schools		Control schools		Difference between SLV-I and Control^b	SLV-I schools		Control schools		Difference between SLV-I and Control^b
	Students	% Total Students	Students	% Total Students	Difference between SLV-I and Control^b	Students	% Total Students	Students	% Total Students	Difference between SLV-I and Control^b
TOTAL STUDENTS	9,027	100 %	4,534	100 %	0 %	9,145	100 %	4,796	100 %	0 %
Not vaccinated	5,356	59.3 %	3,195	70.5 %	−11.2 %	6,486	59.6 %	3,432	71.6 %	−12.0 %
Total vaccinated	3,671	40.7 %*	1,339	29.5 %*	11.2 %^d***	3,698	40.4 %**	1,364	28.4 %**	12.0 %^d***
Vaccinated elsewhere^c	2,474	27.4 %	1,339	29.5 %	−2.1 %	2,659	29.1 %	1,364	28.4 %	0.6 %
Vaccinated at SLV-I	1,197	13.3 %^c	n/a	n/a	13.3 %	1,039	11.4 %	n/a	n/a	11.4 %

n/a: not applicable
a: Only first clinics at each SLV-I school (excluding the vaccinated children at the second vaccination clinics (2.0 % among all students in Year 1))
b: The differences in the proportion between the column of “SLV-I schools (% Total Students)” and “Control schools (% Total Students)”
c: Identified as receiving at least the 1st dose outside the SLV-I schools in the New York State Immunization Information System (NYSIIS)
d: Primary effectiveness measure included in our cost-effectiveness analysis model
*: 40.7 % was significantly greater than 29.5 % (p-value < 0.0001) in Year 1
**: 40.4 % was significantly greater than 28.4 % (p-value < 0.0001) in Year 2
***: Primary effectiveness: 11.2 % in Year 1 was marginally smaller than 12.0 % in Year 2 (p-value = 0.092)

ISSN: 1472-6963