Table 2.

Multivariable regression analysis of risk factors associated with active syphilis among prisoners (N = 3,363)

	Men prisoners		Women prisoners
Variables	Crude OR	Adjusted OR	Crude OR	Adjusted OR
Sociodemographic
Age, per year	0.98 (0.96–0.99)		0.94 (0.92–0.97)	0.96 (0.93–0.99)
Reside in MS	1.08 (0.62–1.88)
Drug history
Drug use	1.82 (1.05–1.77)		1.39 (0.76–2.56)
Intravenous drug use	0.71 (0.42–1.20)		0.40 (0.21–0.79)
Sexual history
Homosexual preference	3.51 (1.05–11.68)	4.51 (0.97–20.95)	1.49 (0.63–3.52)
Previously had homosexual intercourse	1.69 (0.66–4.32)		1.50 (0.74–3.05)
Sex with a drug use	1.37 (0.81–2.31)		1.64 (0.88–3.05)
Sex with an IDU	0.55 (0.07–4.09)		3.42 (1.37–8.48)	3.87 (1.40–10.64)*
Fixed sexual partner	0.62 (0.36–1.06)		1.72 (0.93–3.19)
Sexual partner with HIV, hepatitis, or syphilis	2.32 (0.82–6.57)		3.15 (1.28–7.73)
HIV positive	4.69 (2.05–10.71)	3.70 (1.34–10.21)*	2.64 (0.54–12.85)
Irregular condom use	0.85 (0.50–1.45)		1.20 (0.60–2.41)
Urethral discharge	1.55 (0.61–3.93)		0.77 (0.40–1.47)
Warts in the genital region	0.54 (0.07–3.94)		1.75 (0.49–6.20)
Genital ulcer disease	2.42 (0.73–7.97)		6.34 (1.78–22.54)	13.49 (2.79–65.24)*
Other risk behavior
History of STI(s)	2.76 (1.53–4.97)	2.86 (1.30–6.31)*	3.32 (1.56–7.04)
Blood transfusion	0.95 (0.42–2.11)		1.18 (0.47–2.92)
Tattoos	0.75 (0.44–1.28)		0.62 (0.34–1.15)
Piercings	1.90 (0.85–4.26)		0.59 (0.30–1.18)
Surgery	0.98 (0.57–1.66)		1.92 (0.95–3.88)
Mental illness	0.75 (0.43–1.31)		1.20 (0.65–2.21)
Prison
Previous incarceration	1.11 (0.65–1.91)		1.88 (1.02–3.45)	2.23 (1.08–4.63)*
Time in prison, months, mean ± SD	1.00 (0.99–1.00)		0.98 (0.96–1.00)

Adjusted OR = adjusted odds ratio; crude OR = crude odds ratio; HIV = human immunodeficiency virus; IDU = intravenous drug user; SD = standard deviation; STI = sexually transmitted infection.

^*Adjusted for significant interaction term between these variables (P = 0.01).