Table 2 HIV prevalence among incarcerated people in Iran in three consecutive bio-behavioral surveillance surveys in 2010, 2013, and 2017

Overall prevalence

4536

2.1 (1.2, 3.6)

–

5490

1.7 (1.3, 2.1)

–

5785

0.8 (0.6,1.1)

–

Age

 ≤ 25

1111 (24.5)

1.3 (0.7, 2.1)

0.111

670 (12.2)

0.9 (0.4, 2.4)

0.181

689 (11.9)

0.4 (0.1, 1.5)

0.359

 > 25

3421 (75.5)

2.2 (1.7, 2.7)

4820 (87.8)

1.8 (1.4, 2.3)

5091 (88.1)

0.8 (0.6, 1.1)

Sex

Male

4337 (95.6)

2.1 (1.9, 3.6)

0.910

5387 (98.1)

1.7 (1.3, 2.1)

0.401

5435 (94.0)

0.8 (0.6, 1.0)

0.916

Female

199 (4.4)

1.9 (0.6, 5.9)

103 (1.9)

0.0 (0.0, 3.5)

350 (6.0)

0.9 (0.2, 5. 9)

Level of education

High school or less

4360 (96.2)

2.0 (1.7, 2.5)

0.187

5204 (95.0)

1.8 (1.4, 2.2)

0.231

5361 (92.9)

0. 9 (0.7, 1.2)

0.011

More than high school

172 (3.8)

0.6 (0.09, 4.4)

277 (5.0)

0.8 (0.2, 3.01)

411 (7.1)

0.01 (0.001, 0.7)

Marital status

Never married

1663 (36.9)

2.6 (1.9, 3.5)

 < 0.001

1825 (33.2)

2.7 (1.99, 3.7)

 < 0.001

1915 (33.1)

0.9 (0.6, 1.5)

0.548

Currently married

2415 (53.6)

1.08 (0.7, 1.6)

2998 (54.5)

0.7 (0.5, 1.1)

2939 (50.8)

0. 7 (0.4, 1.1)

Previously married

428 (9.5)

4.2 (2.7, 6.6)

661 (12.3)

3.1 (1.8, 5.3)

928 (16.1)

0.7 (0.3, 1.6)

Incarceration history

Yes

1872 (46.4)

2.9 (2.2, 3.7)

 < 0.001

3260 (59.4)

2.4 (1.9, 3.1)

 < 0.001

3419 (59.1)

0.9 (0.7, 1.4)

0.080

No

2166 (53.6)

1.25 (0.86,1.81)

2228 (40.6)

0.58 (0.32, 1.07)

2362 (40.9)

0.48 (0.23, 1.01)

Ever had non-injection drug use

Yes

3330 (73.5)

2.5 (2.0, 3.1)

 < 0.001

4367 (79.6)

2.0 (1.6, 2.6)

0.002

4424 (76.5)

0.9 (0.7, 1.3)

0.094

No

1200 (26.5)

0.4 (0.2, 1.0)

1119 (20.4)

0.4 (0.1, 1.2)

1360 (23.5)

0.2 (0.0, 1.3)

Ever had drug injection

Yes

726 (16.0)

8.1 (4.6, 13.8)

 < 0.001

991 (22.7)

6.3 (4.8, 8.3)

 < 0.001

705 (12.2)

3.9 (2.7, 5.7)

 < 0.001

No

3803 (84.0)

0.9 (0.5, 1.6)

3368 (77.3)

0.7 (0.4, 1.0)

5065 (87.8)

0.3 (0.2, 0.5)

Age at first drug use

 ≤ 18

1399 (42.6)

3.5 (2.6, 4.6)

0.001

1945 (44.5)

2.9 (2.2, 3.9)

 < 0.001

2059 (46.9)

1.1 (0.7, 1.7)

0.253

 > 18

1884 (57.4)

1.7 (1.2, 2.4)

2422 (55.5)

1.2 (0.8, 1.9)

2329 (53.1)

0.8 (0.5, 1.3)

Age at first injection

 ≤ 18

113 (15.9)

12.4 (7.4, 19. 9)

0.036

127 (12.8)

11.3 (6.3, 19.2)

0.031

99 (14.3)

5.3 (2.2, 12.3)

0.487

 > 18

598 (84.1)

6.7 (4.9, 9.0)

864 (87.2)

5.57 (4.06, 7.61)

594 (85.7)

3.8 (2.5, 5.7)

History of tattooing

Yes

2041

3.3 (2.1, 5.4)

 < 0.001

2672 (48.7)

2.6 (1.9, 3.4)

 < 0.001

2733 (47.3)

1.2 (0.8, 1.7)

0.004

No

2492

1.0 (0.5, 2.2)

2815 (51.3)

0.8 (0.5, 1.3)

3051 (52.7)

0.4 (0.2, 0.8)

Condom use at last sex

Yes

–

–

1144 (24.5)

2.0 (1.2, 3.2)

0.307

1267 (25.4)

0. 9 (0.5, 1.6)

0.614

No

–

–

3532 (75.5)

1.5 (0.9, 2.0)

3725 (74.6)

0.7 (0.5, 1.1)

History of same-sex practices

Yes

–

–

562 (12.1)

2.9 (1.8, 4.9)

0.012

714 (14.7)

1.1 (0.6, 2.2)

0.244

No

–

–

4085 (87.9)

1.4 (1.0, 1.9)

4143 (85.3)

0.7 (0.5, 1.0)

Condom use at last same-sex practice

Yes

–

–

33 (6.0)

7.3 (1.8, 24.9)

0.174

36 (5.1)

0

0.515

No

–

–

521 (94.0)

2.7 (1.6, 4.7)

670 (94.9)

1.2 (0.6, 2.4)