Table 1.

Univariate correlates to being 'very likely' to encourage drug-using partners to participate in a clinical trial for an HCV vaccine (n=415)^a

	Willingness to encourage trial participation - n (%)
Characteristicb	Not very likelyc (n=216)	Very likely (n=199)	OR (95% CI)	p-value
Demographic and Serostatus
Male – n(%)	149 (69.0)	79 (39.7)	0.16 (0.08 – 0.34)	<0.001**
White – n(%)	199 (92.1)	190 (95.5)	2.52 (0.80 – 8.00)	0.116
Age – mean (SD)	35.8 (8.8)	34.7 (8.2)	0.97 (0.95 – 1.00)	0.088
Total Monthly Income				0.049*
First quartile ($0 – $200)	51 (23.7)	65 (32.7)	2.82 (1.32 – 6.02)
Second quartile ($201 – $698)	46 (21.4)	51 (25.6)	2.14 (0.98 – 4.66)
Third quartile ($699 – $1100)	55 (25.6)	42 (21.1)	1.48 (0.69 – 3.15)
Fourth quartile ( ≥ $1101)	63 (29.3)	41 (20.6)	Reference
Education (years) – mean (SD)	11.22 (1.97)	11.24 (1.81)	1.03 (0.90 – 1.19)	0.646
Married – n(%)	54 (25.0)	55 (27.6)	1.24 (0.69 – 2.24)	0.470
Uninsured – n(%)	135 (62.5)	140 (70.4)	1.50 (0.86 – 2.62)	0.154
Unemployed – n(%)	82 (38.0)	82 (41.2)	1.00 (0.59 – 1.70)	0.993
Self-report of being in good health – n(%)	132 (61.1)	168 (84.4)	5.49 (2.69 – 11.23)	<0.001**
Incarcerated (past 30 days) – n(%)	56 (25.9)	59 (29.7)	2.11 (1.00 – 4.47)	0.050
HCV seropositive – n(%)	121 (56.0)	131 (65.8)	2.21 (1.27 – 3.83)	0.005**
Substance use in past 6 months
Alcohol – n(%)	92 (42.6)	82 (41.2)	1.03 (0.61 – 1.74)	0.921
Alcohol to intoxication – n(%)	68 (31.5)	51 (25.6)	0.58 (0.33 – 1.01)	0.055
Nonmedical use of prescription drugs – n(%)	186 (86.1)	166 (83.4)	0.86 (0.42 – 1.76)	0.678
Heroin – n(%)	6 (2.8)	16 (8.0)	4.25 (1.13 – 15.94)	0.032*
Methamphetamine – n(%)	13 (6.0)	22 (11.1)	2.89 (1.05 – 8.00)	0.041*
Cocaine – n(%)	24 (11.1)	27 (13.6)	1.20 (0.52 – 2.79)	0.666
Crack – n(%)	5 (2.3)	9 (4.5)	3.15 (0.66 – 15.09)	0.152
Risk behaviord
Injected drugs – n(%)	70 (32.4)	70 (35.2)	1.14 (0.66 – 1.96)	0.642
Injected with unclean needle – n(%)	13 (6.0)	20 (10.1)	1.75 (0.67 – 4.57)	0.252
Distributed unclean needlee – n(%)	7 (3.2)	9 (4.5)	1.01 (0.27 – 3.77)	0.993
Shared injection equipmentf – n(%)	24 (11.1)	29 (14.6)	1.22 (0.56 – 2.65)	0.619
Bleached needles – n(%)	15 (6.9)	18 (9.1)	1.30 (0.52 – 3.22)	0.576
Unprotected sex with PWID – n(%)	36 (16.7)	45 (22.6)	1.80 (0.95 – 3.42)	0.073
Snorted drugs (past 30 days) – n(%)	105 (48.6)	77 (38.7)	0.67 (0.39 – 1.17)	0.158
Network characteristics (n=356)g
Number of injection partners – mean (SD)	0.28 (0.84)	0.17 (0.65)	0.84 (0.59 – 1.21)	0.356
Number of people in personal network who inject – mean (SD)	0.58 (1.05)	0.58 (1.13)	1.05 (0.82 – 1.35)	0.695
Number of people to whom participant talks about injection-related risk reduction – mean (SD)	0.26 (0.78)	0.21 (0.69)	0.87 (0.59 – 1.28)	0.482
Frequency of sharing injection equipment with all network members – mean (SD)	0.59 (2.94)	0.38 (1.85)	0.91 (0.78 – 1.05)	0.179
Number of people with whom participant uses drugs – mean (SD)	1.46 (1.68)	1.24 (1.66)	0.94 (0.79 – 1.12)	0.501
Frequency of drug sharing with all network members – mean (SD)	3.83 (4.52)	3.16 (4.60)	0.97 (0.91 – 1.03)	0.354
Number of network members providing social support – mean (SD)	1.74 (1.23)	1.62 (1.22)	0.91 (0.72 – 1.16)	0.451
Number of network members providing financial support – mean (SD)	0.58 (0.69)	1.05 (0.97)	2.56 (1.62 – 4.04)	<0.001**

PWID: person who injects drugs; OR: odds ratio; CI: confidence interval; SD: standard deviation

^*p-value <0.05;

^**p-value <0.01

^aDoes not include those who reported that the question was not applicable (n=18).

^bAll categorical variables (indicted with a 'n(%)') were dichotomous.

^cIncludes responses "very unlikely", "unlikely", and "likely"

^dThe recall period for risk behaviors listed was 6 months with the exception of snorting, which was assessed based on the past 30 days

^eSold, loaned, or gave needle to someone after using it

^fCookers, cottons, and/or rinse water

^g59 participants reported no network members