Table 1 Prevalence and odds of C. trachomatis and N. gonorrhoeae infections by socio-demographic and behavioral characteristics and other STIs

FSW category

 High-tier

1192

5.54

Reference

—

16.36

Reference

—

 Middle-tier

1298

5.24

0.94 (0.67–1.34)

0.74

16.87

1.04 (0.84–1.28)

0.73

 Low-tier

609

8.04

1.49 (1.02–2.19)

0.04

20.03

1.28 (1.00–1.65)

0.05

Age group (years)

 15–20

617

8.10

Reference

—

27.88

Reference

—

 21–25

1149

5.05

0.60 (0.41–0.89)

0.01

18.53

0.59 (0.47–0.74)

<0.001

 26–30

648

4.94

0.59 (0.37–0.93)

0.02

10.03

0.29 (0.21–0.39)

<0.001

 >30

685

6.28

0.76 (0.50–1.16)

0.20

12.55

0.37 (0.28–0.49)

<0.001

Geographic area

 Other provinces

2301

5.43

Reference

—

16.30

Reference

—

 Guangxi

798

7.27

1.36 (0.99–1.88)

0.06

20.18

1.30 (1.06–1.59)

0.01

Education level

 Primary school or below

460

7.17

Reference

—

14.56

Reference

—

 Secondary school

2074

5.59

0.77 (0.51–1.14)

0.19

17.84

1.27 (0.96–1.69)

0.09

 High school or above

562

6.05

0.83 (0.51–1.37)

0.47

17.61

1.25 (0.89–1.76)

0.19

Marital status

 Never married

1890

5.38

Reference

—

19.79

Reference

—

 Married

1113

6.65

1.25 (0.92–1.70)

0.15

13.57

0.64 (0.52–0.78)

<0.001

 Divorced

87

5.75

1.07 (0.42–2.70)

0.88

11.49

0.53 (0.27–1.03)

0.06

Consistent condom use in past month

 Yes

1611

6.33

Reference

—

16.57

Reference

—

 No

1488

5.44

0.85 (0.63–1.15)

0.29

17.08

1.11 (0.92–1.34)

0.27

Other STIs

 Syphilis

200

9.00

1.64 (0.99–2.73)

0.06

14.00

0.77 (0.51–1.15)

0.20

 Gonorrhoea

183

—

—

—

28.41

1.99 (1.43–2.79)

<0.001

 Chlamydia

536

9.70

1.99 (1.43–2.79)

<0.001

—

—

—