Table 3.

Unadjusted and Multivariate Risks of Hepatitis B Virus (HBV) Infection According to Timing of HBV Vaccination and Time of Human Immunodeficiency Virus (HIV) Diagnosis, US Military HIV Natural History Study, 1989–2008

Characteristic	Unadjusted Model			Multivariate Model 1a			Multivariate Model 2a
	HR	95% CI	P Value	HR	95% CI	P Value	HR	95% CI	P Value
Age at HIV diagnosis, per 10-year increase	0.75	0.61, 0.93	0.01	0.82	0.66, 1.02	0.08	0.83	0.67, 1.03	0.10
Gender
Female	1	Referent		1	Referent		1	Referent
Male	7.12	2.64, 19.16	<0.001	7.97	2.95, 21.52	<0.001	8.04	2.98, 21.72	<0.001
Race/ethnicity
Caucasian	1	Referent		1	Referent		1	Referent
African-American	1.37	1.01, 1.85	0.04	1.38	1.01, 1.89	0.04	1.39	1.02, 1.90	0.04
Other	0.73	0.41, 1.29	0.28	0.74	0.42, 1.33	0.31	0.76	0.43, 1.35	0.35
Branch of service
Army	1	Referent
Navy	1.21	0.84, 1.74	0.30
Air Force	1.07	0.72, 1.60	0.74
Other/civilian	0.89	0.51, 1.57	0.69
Body mass indexb, per 1-unit increase	0.95	0.89, 1.01	0.10
CD4 cell countc, per 100-cells/μL increase	0.95	0.90, 1.01	0.09	0.98	0.92, 1.04	0.45	0.98	0.92, 1.04	0.48
HIV RNA loadc, per 0.5-log10 copies/mL increase	1.73	1.28, 2.35	<0.001
AIDS-defining illnessc
No	1	Referent
Yes	0.64	0.30, 1.36	0.35
Prior sexually transmitted infectionc
None	1	Referent
Any	1.34	1.00, 1.80	0.05
Gonorrhea	1.20	0.84, 1.73	0.32
Chlamydia	1.39	0.93, 2.08	0.11
Herpes	0.82	0.45, 1.47	0.50
Syphilis	1.73	1.14, 2.60	0.01	1.47d	0.96, 2.24	0.07	1.45d	0.95, 2.21	0.09
Positive for antibodies to hepatitis C virusc
No	1	Referent
Yes	0.74	0.24, 2.33	0.61
HAART usec
None	1	Referent		1	Referent		1	Referent
HAART	0.27	0.18, 0.41	<0.001	0.38	0.24, 0.60	<0.001	0.38	0.24, 0.61	<0.001
HBV vaccination before HIV diagnosis
Yes (VB + VBA)	0.65	0.43, 0.97	0.03	0.68	0.45, 1.04	0.08
No (VA + NV)	1	Referent		1	Referent
HBV vaccination groupc,e
VB	0.50	0.27, 0.93	0.03				0.38	0.20, 0.75	0.005
VBA	1.28	0.73, 2.27	0.39				1.08	0.61, 1.92	0.80
VA	0.91	0.65, 1.28	0.59				0.87	0.62, 1.23	0.44
NV	1	Referent					1	Referent

Abbreviations: AIDS, acquired immunodeficiency syndrome; CI, confidence interval; HAART, highly active antiretroviral therapy; HBV, hepatitis B virus; HIV, human immunodeficiency virus; HR, hazard ratio; NV, not vaccinated; VA, vaccinated after; VB, vaccinated before; VBA, vaccinated before and after.

^aIn the final multivariate models, results were stratified by era of HIV diagnosis and further adjusted for year of HIV diagnosis.

^bWeight (kg)/height (m)².

^cTime-updated covariate.

^dCompared with not having syphilis.

^eRelative to HIV diagnosis.