Table 2.

Multivariate analysis of factors associated with syphilis infection

Factor	Adjusted OR (95%CI)	P
Age group in years
16-19	1.0 (Reference)	-
20-29	2.62 (1.57, 4.36)	< 0.001
30-39	4.37 (2.57, 7.42)	< 0.001
40-	7.81 (4.36, 14.01)	< 0.001
Site city
Yangzhou	1.0 (Reference)	-
Changzhou	14.35 (6.43, 32.03)	< 0.001
Jiangmen	9.51 (3.76, 24.08)	< 0.001
Maoming	10.62 (4.61, 24.47)	< 0.001
Wuzhou	4.17 (1.90, 9.17)	< 0.001
Hezhou	13.54 (6.17, 29.71)	< 0.001
Qionghai	9.44 (4.00, 22.29)	< 0.001
Sanya	8.14 (3.48, 19.02)	< 0.001
Education
Primary or less	2.10 (1.34, 3.30)	0.001
Junior high school	1.56 (1.04, 2.35)	0.031
Senior high school and above	1.0 (Reference)	-
Typology
High-tier	1.0 (Reference)	-
Middle-tier	1.68 (1.15, 2.46)	0.008
Low-tier	4.05 (2.60, 6.31)	< 0.001
Injecting drug use
Yes	6.17 (2.13, 17.81)	0.001
No	1.0 (Reference)	-

OR odds ratio, CI confidence interval.