Association between Semen Exposure and Incident Bacterial Vaginosis

Table 3

Results of cohort analyses of associations between selected factors and incident bacterial vaginosis among HIV-uninfected U.S. women, HERS, 1993–2000*.

	Control visits	Case visits	Bivariable model		Multivariable model^†
	No.	No.	OR	(95% CI)	aOR	(95% CI)
Time-independent factors
Study site
Site 1	437	65	Referent		Referent
Site 2	185	77	2.7	(1.7, 4.2)	1.9	(1.2, 3.1)
Site 3	271	94	2.4	(1.5, 3.7)	1.7	(1.0, 2.7)
Site 4	372	63	1.1	(0.7, 1.7)	1.5	(1.0, 2.3)
Age at baseline (in years)
16–24	51	7	0.9	(0.3, 2.1)
25–34	386	106	1.4	(0.9, 2.2)
35–44	597	139	1.1	(0.7, 1.6)
45+	231	47	Referent
Race
Black	568	201	2.5	(1.8, 3.5)	1.9	(1.3, 2.7)
Other	697	98	Referent		Referent
Education at baseline
<High school	367	99	1.4	(1.0, 2.1)
High school	436	101	1.1	(0.8, 1.6)
>High school	457	99	Referent
Time-dependent factors
Visit (0–15)			0.9	(0.9, 1.0)	0.94	(0.9, 1.0)
Trichomoniasis at preceding visit
Yes	100	60	2.1	(1.4, 3.2)	1.7	(1.1, 2.6)
No	1163	239	Referent		Referent
Vaginal Candidal culture at preceding visit
Yes	393	91	1.0	(0.8, 1.3)
No	864	208	Referent
Human papillomavirus at preceding visit
Yes	278	84	1.3	(0.9, 1.7)
No	975	210	Referent
Spermatozoa detected on Gram stain
Yes	76	43	2.3	(1.6, 3.3)	1.9	(1.3, 2.9)
No	1189	256	Referent		Referent
Sexual behavior during previous 6 months^‡
Frequent coitus, inconsistent condom use	411	139	2.3	(1.6, 3.3)	1.9	(1.3, 2.8)
Frequent coitus, consistent condom use	129	35	1.8	(1.1, 2.9)	1.9	(1.2, 3.1)
Infrequent coitus, inconsistent condom use	244	49	1.4	(0.9, 2.0)	1.2	(0.8, 1.8)
Infrequent coitus, consistent condom use	138	23	1.1	(0.6, 1.9)	1.1	(0.6, 2.0)
Not sexually active	341	52	Referent		Referent
Female sex partner during previous 6 months
Yes	92	25	1.2	(0.7, 1.8)
No	1169	272	Referent
Douching within 48 hours
Yes	44	13	1.1	(0.6, 2.0)
No	1215	285	Referent
Current hormonal contraception use
Yes	92	9	0.4	(0.2, 0.9)	0.4	(0.2, 0.8)
No	1171	289	Referent		Referent
Current injection drug use
Yes	160	58	1.5	(1.0, 2.2)
No	1104	241	Referent
Crack use during previous 6 months
Yes	139	66	2.0	(1.3, 2.9)
No	1125	233	Referent
Cigarette use during previous 6 months
Yes	837	230	1.7	(1.2, 2.4)	1.5	(1.0, 2.1)
No	427	69	Referent		Referent

*Findings from unconditional logistic regression model, using generalized estimating equations, based on 299 case visits (i.e., visits with incident bacterial vaginosis) and 1265 control visits (i.e., visits without incident bacterial vaginosis) completed by 375 participants.
^†Adjusted for all variables in column.
^‡Frequent coitus defined as ≥4 times per month and infrequent coitus defined as <4 times per month.