Table 5 HCV prevalence by different behavioral and demographic characteristics among Vietnamese FSW by different years (2010–2014) (N = 1026)

Age

<=25 yr

0 (0/29)

5.66 (3/53)

3.53 (3/85)

5.98 (11/184)

3.37 (7/208)

4.29 (24/559)

0.498

0.849

>25 = 1

0 (0/20)

0 (0/57)

1.23 (1/81)

0.63 (1/159)

0.67 (1/150)

0.64 (3/467)

0.918

0.73

Marital status

Not Married

0 (0/28)

0 (0/58)

1.08 (1/93)

2.81 (5/178)

1.27 (2/157)

1.56 (8/514)

0.493

0.327

Married

0 (0/21)

5.77 (3/52)

4.11 (3/73)

4.24 (7/165)

2.99 (6/201)

3.71 (19/512)

0.757

0.761

Length of working

<6 m

0 (0/9)

0 (0/71)

0 (0/65)

2.56 (5/195)

1.72 (3/174)

1.56 (8/514)

0.46

0.209

> = 6 m

0 (0/40)

7.69 (3/39)

4.04 (4/99)

4.73 (7/148)

2.72 (5/184)

3.73 (19/510)

0.377

0.884

Education

<MS

0 (0/30)

1.61 (1/62)

3.33 (3/90)

6.29 (9/143)

3.11 (6/193)

3.67 (19/518)

0.301

0.317

> = MS

0 (0/19)

4.17 (2/48)

1.35 (1/74)

1.50 (3/200)

1.21 (2/165)

1.58 (8/506)

0.637

0.499

Community service

Yes

0 (0/47)

2.78 (2/72)

2.65 (4/151)

3.45 (11/319)

2.25 (7/311)

2.67 (24/900)

0.69

0.657

No

0 (0/2)

3.85 (1/26)

0 (0/15)

4.17 (1/24)

2.13 (1/47)

2.63 (3/114)

0.928

0.886

Condom use in the last sex

No

0 (0/8)

0 (0/17)

4.55 (1/22)

3.70 (1/27)

0 (0/11)

2.35 (2/85)

0.819

0.695

Yes

0 (0/40)

3.30 (3/91)

2.08 (3/144)

3.49 (11/315)

2.31 (8/346)

2.67 (25/936)

0.66

0.761

Condom use in the last month

Inconsistent

0 (0/22)

2.33 (1/43)

5.56 (3/54)

6.76 (5/74)

0 (0/63)

3.52 (9/256)

0.183

0.994

Consistent

0 (0/27)

3.08 (2/65)

0.90 (1/111)

2.26 (6/265)

2.71 (8/295)

2.23 (17/763)

0.727

0.414

Drug use

Yes

0 (0/2)

100.0 (1/1)

33.33 (2/6)

63.64 (7/11)

33.33 (4/12)

43.75 (14/32)

0.248

0.772

No

0 (0/47)

1.85 (2/108)

1.25 (2/160)

1.51 (5/332)

1.16 (4/346)

1.31 (13/993)

0.904

0.077

Types of venues

Low-paying

0.00 (0/41)

3.80 (3/79)

2.46 (3/122)

4.35 (7/161)

3.45 (6/174)

3.29 (19/577)

0.681

0.93

Medium-paying

0.00 (0/3)

0.00 (0/19)

3.13 (1/32)

2.86 (1/32)

1.10 (2/181)

1.87 (7/375)

0.732

0.716

High-paying

0.00 (0/5)

0.00 (0/11)

0.00 (0/11)

0.00 (0/21)

0.00 (0/2)

0.00 (0/51)

n/a

n/a

HIV knowledge

Low < =5

0 (0/29)

5.26 (2/38)

2.88 (3/104)

4.26 (8/188)

3.24 (7/216)

3.48 (20/575)

0.756

0.705

High > 5

0 (0/20)

1.39 (1/72)

1.61 (1/62)

2.58 (4/155)

0.70 (1/142)

1.55 (7/451)

0.723

0.974