Table 3.

Multivariate Analysis of Characteristics Associated With Infection With a Beijing Strain, China, 2009–2010

Characteristic	Beijing vs Non-Beijing
	Adjusted OR (95% CI)	P Value
Regions		<.001
Sichuan	1.00
Guangxi	1.46 (.97–2.20)
Shanghai	2.95 (2.03–4.29)
Shandong	3.20 (2.05–4.97)
Henan	8.30 (4.77–14.44)
Heilongjiang	5.40 (3.24–9.00)
Genotypic cluster	1.95 (1.40–2.71)	<.001
Age (y)		.02
<25	1.00
25–44	0.76 (.51–1.14)
45–64	0.60 (.39–.90)
≥65	0.48 (.31–.75)
Unknown	0.47 (.14–1.60)

The ORs were adjusted by logistic regression model for all other variables in this table.

Abbreviations: CI, confidence interval; OR, odds ratio.