Table 3.

Chronic HCV infection (HCV RNA positivity) among injection drug users who had antibodies to HCV^a, in the San Francisco Bay area between 1998–2000

Characteristic	No.	% HCV RNA positive	OR (95% CI)	p-valueb
Overall	2092	82.1%
Age
18–29 years	129	69.8%	1.00 (referent)	<0.0001 c
30–39 years	415	77.3%	1.48 (0.95–2.30)
40–49 years	1048	82.9%	2.10 (1.40–3.17)
≥50 years	500	87.4%	3.01 (1.90–4.76)
Duration injection drug use
≤9 years	235	74.5%	1.00 (referent)	0.001 c
10–19 years	390	81.5%	1.51 (1.03–2.23)
20–29 years	733	82.3%	1.59 (1.12–2.25)
≥30 years	677	84.8%	1.91 (1.33–2.74)
Gender
Male	1461	83.8%	1.00 (referent)
Female	600	77.8%	0.68 (0.54–0.86)	0.001
Race
African American	1061	88.5%	1.00 (referent)
White	759	77.5%	0.45 (0.35–0.58)	<0.0001
Latino	155	71.0%	0.32 (0.21–0.47)	<0.0001
Others	117	68.4%	0.28 (0.18–0.43)	<0.0001
HBV infection
Resolved	1641	83.1%	1.00 (referent)
Chronic	53	54.7%	0.25 (0.14–0.43)	<0.0001
Never infected	302	81.8%	0.91(0.66–1.26)	0.57
HIV-1
Uninfected	1827	80.8%	1.00 (referent)
Infected	262	90.8%	2.36 (1.53–3.65)	<0.0001

^aInfection with HCV was defined by HCV antibody. Chronic HCV infection was defined by HCV RNA.

^bP value from chi-square test unless indicated otherwise

^cP value for linear trend