Table 1

Association between participant characteristics and syphilis status in women in the early cohort (n=3692)

VariableSyphilis negative n=3414 (92.5%)Syphilis positive n=278 (7.5%)Syphilis seroprevalence crude POR
(95% CI)
P valueSyphilis seroprevalence adjusted POR
(95% CI)
P value
Demographics
 Age category (years)0.0070.001
  16–29962 (28.2)64 (23.0)0.90 (0.45 to 1.80)0.7761.22 (0.59 to 2.56)0.591
  30–391521 (44.6)154 (55.4)1.38 (0.71 to 2.67)0.3441.31 (0.66 to 2.62)0.443
  40–49795 (23.3)50 (18.0)0.86 (0.42 to 1.73)0.6630.64 (0.31 to 1.32)0.228
  ≥50136 (4.0)10 (3.6)RefRefRefRef
 Black race1925 (56.4)203 (73.0)2.09 (1.59 to 2.75)<0.0011.95 (1.46 to 2.60)<0.001
 Hispanic ethnicity914 (26.8)61 (21.9)0.77 (0.57 to 1.03)0.080
 Single relationship status2155 (63.2)183 (66.1)1.13 (0.87 to 1.47)0.347
 Low Income (<$12 000/year)1934 (58.5)202 (76.8)2.35 (1.75 to 3.15)<0.0012.01 (1.48 to 2.73)<0.001
 Self-reported history of syphilis29 (0.85)48 (17.3)24.6 (15.2 to 39.7)<0.001
 Currently pregnant69 (2.0)10 (3.6)1.82 (0.93 to 3.58)0.082
Medical comorbidities
 HIV infection2501 (73.3)232 (83.5)1.84 (1.33 to 2.55)<0.0011.84 (1.30 to 2.60)<0.001
 Hepatitis C (antibody positive)1072 (31.4)131 (47.3)1.96 (1.53 to 2.51)<0.0011.46 (1.08 to 1.96)0.013
Drug and alcohol use
 Problem alcohol use
 (>7 drinks/week)
384 (11.3)50 (18.0)1.69 (1.22 to 2.34)0.001
 Active or prior drug use2548 (74.8)259 (93.2)4.60 (2.87 to 7.38)<0.0013.25 (1.94 to 5.44)<0.001
 Active or prior IDU1021 (29.9)109 (39.2)1.51 (1.18 to 1.94)0.001
Sexual history
 Number of lifetime sex partners<0.001<0.001
 >100215 (6.3)50 (18.0)3.71 (2.62 to 5.27)<0.0012.88 (1.98 to 4.19)<0.001
 11–100866 (25.4)82 (29.5)1.51 (1.14 to 2.00)0.0041.18 (0.87 to 1.60)0.296
 0–102332 (68.3)146 (52.5)RefRefRefRef
 Transactional sex (ever)1065 (31.3)179 (64.6)4.00 (3.10 to 5.18)<0.001
  • Values expressed as n (% of non-missing results); reference levels for variables: age (≥50 years old), race (white, Asian, Native American, Pacific Islander and other), ethnicity (non-Hispanic), relationship status (married/living with a partner), income (US$≥12 000), self-reported history of syphilis (no self-reported history of syphilis), currently pregnant (not pregnant), HIV status (HIV negative); hepatitis C (negative), problem alcohol use (≤7 drinks a week), active or historical use of cocaine/crack, heroin, methamphetamines or other non-IDU drugs (no active or historical drug use); number of lifetime sex partners (0–10 lifetime partners) and history of transactional sex (reporting never having sex for drugs, money or shelter); missing data: income (n=123, 3.3%), self-reported history of syphilis (n=3, 0.1%), currently pregnant (n=32, 0.9%), marital status (n=7, 0.2%), HCV antibody (n=3, 0.1%), alcohol use (n=83, 2.3%), transactional sex (n=16, 0.4%), active or historical use of cocaine/crack, heroin, methamphetamines or other non-IDU drugs (n=6, 0.2%) and number of lifetime sex partners (n=1, <0.1%). In the multivariable model for women enrolled in the early WIHS cohorts (1994–2002), there were 3692 women of which data for 3562 were used. Backward selection with an alpha level of removal of 0.2 was used, and problem alcohol use was removed from the model.

  • IDU, injection drug use; POR, prevalence OR; WIHS, Women’s Interagency HIV Study.