Table 3. Univariate and multivariate analyses comparing H1N1(2009) and ARI patients.

Patient characteristics		Univariate analysis			Multivariate analysis, symptoms only			Multivariate analysis with lab & CXR
		Crude OR	(95% CI)	p-Value	Adjusted OR	(95% CI)	p-Value	Adjusted OR	(95% CI)	p-Value
Constitutional symptoms, %	Self-reported feverishness/chills/rigors	6.5	(3.2–13.4)	<0.001	4.0	(1.8–9.0)	0.001	3.8	(1.6–9.0)	0.003
	Headache	2.1	(0.9–4.8)	0.075		-		2.8	(0.9–9.1)	0.083
	Myalgia	1.2	(0.5–2.7)	0.674		-			-
	Lethargy/malaise	0.8	(0.2–3.0)	0.734		-			-
	Nausea/vomitting/anorexia	0.1	(0.0–0.6)	0.007	0.1	(0.0–0.4)	0.002	0.1	(0.0–0.3)	0.002
Respiratory symptoms, %	Cough	2.3	(1.2–4.4)	0.009	2.0	(0.9–4.3)	0.073	2.2	(1.0–5.0)	0.057
	Sorethroat	0.8	(0.4–1.3)	0.321		-			-
	Rhinorrhea/nasal congestion	1.9	(1.1–3.3)	0.024	2.5	(1.3–5.1)	0.009	2.5	(1.2–5.3)	0.018
Body temperature cut-off points	T≥38.1°C	6.5	(3.4–12.5)	<0.001	6.4	(2.8–14.4)	<0.001	6.7	(2.7–16.7)	<0.001
	T≥37.8°C	4.2	(2.3–7.5)	<0.001		-			-
	T≥37.5°C	4.8	(2.6–8.7)	<0.001		-			-
Laboratory and radiological findings	Absence of leucocytosis (leucocytes >9.3×10̂9/L)	5.0	(2.5–10.2)	<0.001		-		4.5	(1.9–10.7)	0.001
	Lymphopenia (lymphocytes <0.9×10̂9/L)	2.6	(1.3–5.1)	0.006		-			-
	Normal chest radiograph	3.3	(1.0–10.5)	0.047		-		6.2	(1.2–30.6)	0.026