# Table 1 Logistic regression models for association of risk factors with STI prevalence

Variable   N with STI/ total N (STI prevalence) Univariable Multivariable 1 (N = 957) Multivariable 2 (N = 957)
OR (95% CI) p OR p OR p
Age group 16–19 61/419 (14.6) 1 0.042 1 0.95
20–25 114/584 (19.5) 1.42 (1.01, 2.00) 1.01 (0.68, 1.51)
Sex Male 23/214 (10.8) 1 0.004 1 0.001 1 0.001
Female 152/789 (19.3) 1.98 (1.24, 3.16) 2.77 (1.54, 4.98) 2.64 (1.52, 4.57)
Relationship status Single 21/177 (11.9) 0.65 (0.39, 1.10) 0.005 1.48 (0.72, 3.04) 0.02 1.23 (0.67–2.27) 0.007
Boyfriend/girlfriend 70/368 (19.0) 1.14 (0.80, 1.64) 1.82 (1.05, 3.12) 1.70 (1.09–2.63)
Married 74/434 (17.1) 1 1 1
Divorced/widowed 10/24 (41.7) 3.47 (1.49, 8.12) 4.10 (1.50, 11.25) 3.71 (1.51–9.06)
New partner in the last 3 months Yes 35/157 (22.3) 1.45 (0.95, 2.20) 0.083 0.69 (0.36, 1.30) 0.25
No 129/846 (16.6) 1 1
No of sexual partners in last 3 months 0 31/293 (10.6) 1  < 0.001 1 0.16
1 119/623 (19.1) 2.00 (1.31, 3.04) 1.07 (0.54, 2.12)
2+  25/87 (28.7) 3.41 (1.88, 6.18) 2.09 (0.83, 5.25)
No of lifetime partners 0 11/186 (5.9) 1   1 0.004 1
1 54/388 (13.9) 2.57 (1.31, 5.04)  < 0.001 2.19 (0.85, 5.64) 2.09 (0.98, 4.44)  < 0.001
2 +  110/429 (25.6) 5.49 (2.87, 10.47) 3.89 (1.47, 10.29) 3.98 (1.93, 8.19)
History of STI treatment Yes 22/79 (27.9) 1.94 (1.15, 3.28) 0.012 0.75 (0.40, 1.40) 0.36
No 153/924 (16.6) 1 1
Partner ever had an STI Yes 17/43 (39.5) 3.32 (1.76,6.26)  < 0.001 1.90 (0.88, 4.07) 0.10
No 158/960 (16.5) 1 1
HIV status (N = 957) Positive 18/50 (36.0) 2.79 (1.53, 5.11)  < 0.001 2.05 (1.05, 4.01) 0.04 1.95 (1.02, 3.72) 0.04
Negative 152/907 (16.8) 1 1 1
Use of condoms (N = 817) Always 15/116 (12.9) 0.70 (0.38, 1.28) 0.004 0.65 (0.32, 1.35) 0.12
Sometimes 82/319 (25.7) 1.63 (1.13, 2.34) 1.27 (0.81, 1.99)
Never 67/382 (17.5) 1 1
Perceived STI risk None/low 93/721 (12.9) 1  < 0.001 1 0.01 1  < 0.001
Medium/high 82/282 (29.1) 2.77 (1.98, 3.88) 1.67 (1.12, 2.49) 1.98 (1.37, 2.87)
Use of hormonal contraception (N = 789) Yes 87/451 (19.3) 1.00 (0.70, 1.44) 0.98
No 65/338 (19.2) 1
Past or current pregnancy (N = 789) Yes 13/36 (36.1) 2.50 (1.23, 5.05) 0.011 2.70 (1.27, 5.78) 0.01 2.55 (1.21, 5.39) 0.014
No 139/753 (18.5) 1 1 1
1. Multivariable Model 1: includes all potential risk factors and Multivariable Model 2: includes potential risk factors that were associated with STI infection in Model 1 ( female gender, relationship status, number of lifetime sexual partners, HIV status, perceived STI risk and past/current pregnancy)