Table 5.

Incidence rate ratio (IRR) of ILI and laboratory-confirmed influenza among students in intervention and control schools

Outcome	IR per 1,000 student-weeks		IRR (95% CI)	P-value	AIRR* (95% CI)	P-value
	Intervention	Control
ILI	22	27	0.8 (0.5, 1.3)	0.4	0.8 (0.5, 1.3)	0.4
Laboratory-confirmed influenza	3	6	0.5 (0.3, 0.8)	0.01	N/A	–

AIRR = adjusted incidence rate ratio; ILI = influenza-like illness; IR = incidence rate; N/A = not applicable. Note: We did not find any factors that were statistically significant for laboratory-confirmed influenza in univariate analyses.

* Adjusted for gender.