Table 4.

Univariable and Multivariable Logistic Regression Models for 1-1 Match Case-Control to Predict HBV Infection, n = 50 Pairs, Male Injection Drug Users, Bac Ninh Province, Vietnam.

Effect	Univariable Models			Multivariable Model*
	OR	95% CI	p-value	OR	95% CI	p-value
Length of drug injection (yrs)**	1.14	0.93–1.41	0.206	1.10	0.88–1.37	0.396
Sharing drug solution through frontloading, last injection	4.33	1.24–15.21	0.022	3.82	1.06–13.80	0.041
No. of sexual partners, past 12 months	1.03	0.96–1.11	0.383
Having had sex with a female sex worker, past 12 months	1.07	0.52–2.22	0.853
Having Chlamydial infection (PCR) or HSV-2 infection (EIA)	2.60	0.93–7.29	0.069	2.15	0.69–6.70	0.188
Being vaccinated against hepatitis B, at least one dose	0.57	0.17–1.95	0.372	0.89	0.23–3.46	0.864

OR denotes odds ratio; CI, confidence interval; PCR, polymerase chain reaction; EIA, enzyme-linked immunosorbent assay;

^*Multivariable model included Length of drug injection, Sharing drug solution through frontloading at last injection, Having chlamydial infection or HSV-2 infection, and Being vaccinated against hepatitis B;

^**Odds ratio for one year increase.