Table 3.

Univariate correlates to being 'very likely' to participate in a clinical trial for an HCV vaccine (n=165)^a

	Willingness to participate in HCV Vaccine trial
Characteristicb	Not very likelyc (n=93)	Very likely (n=72)	OR (95% CI)	p-value
Demographic
Male – n(%)	55 (59.1)	30 (41.7)	0.42 (0.17 – 1.05)	0.064
White – n(%)	87 (93.6)	69 (95.8)	2.06 (0.28 – 15.23)	0.479
Age – mean (SD)	36.6 (9.4)	37.0 (9.8)	1.01 (0.97 – 1.06)	0.516
Total monthly income				0.133
First quartile ($0 – $200)	22 (23.6)	18 (25.0)	3.49 (1.02 – 11.90)
Second quartile ($201 – $698)	23 (24.7)	18 (25.0)	2.88 (0.88 – 9.43)
Third quartile ($699 – $1100)	19 (20.4)	23 (31.9)	3.96 (1.12 – 13.99)
Fourth quartile ( ≥ $1101)	29 (31.2)	13 (18.1)	Reference
Education (years) – mean (SD)	11.7 (1.7)	11.0 (2.1)	0.78 (0.61 – 0.99)	0.044*
Married – n(%)	28 (30.1)	29 (40.3)	1.89 (0.77 – 4.62)	0.162
Uninsured – n(%)	60 (64.5)	42 (58.3)	0.67 (0.28 – 1.57)	0.354
Unemployed – n(%)	21 (22.6)	29 (40.3)	3.78 (1.51 – 9.45)	0.004**
Self-report of being in good health – n(%)	59 (63.4)	51 (70.8)	1.07 (0.46 – 2.48)	0.884
Incarcerated (past 30 days) – n(%)	6 (6.5)	5 (6.9)	0.61 (0.11 – 3.41)	0.570
Substance use in past 6 months
Alcohol – n(%)	41 (44.1)	33 (45.8)	1.20 (0.53 – 2.70)	0.664
Alcohol to intoxication – n(%)	32 (34.4)	20 (27.8)	0.93 (0.37 – 2.33)	0.881
Nonmedical use of prescription drugs – n(%)	74 (79.6)	66 (91.7)	4.11 (1.24 – 13.69)	0.021
Heroin – n(%)	1 (1.1)	4 (5.6)	3.44 (0.30 – 39.85)	0.322
Methamphetamine – n(%)	6 (6.5)	7 (9.7)	2.23 (0.44 – 11.21)	0.331
Cocaine – n(%)	8 (8.6)	8 (11.1)	1.39 (0.30 – 6.46)	0.674
Crack – n(%)	4 (4.3)	1 (1.4)	0.14 (0.00 – 5.90)	0.306
Risk behaviord
Injected drugs – n(%)	8 (8.6)	9 (12.5)	1.65 (0.43 – 6.32)	0.464
Injected with unclean needle – n(%)	2 (2.2)	2 (2.8)	0.63 (0.02 – 18.96)	0.793
Distributed unclean needlee – n(%)	1 (1.1)	0 (0.0)	---	---
Shared injection equipmentf – n(%)	3 (3.2)	2 (2.8)	0.36 (0.02 – 7.87)	0.513
Bleached needles – n(%)	3 (3.2)	1 (1.4)	0.35 (0.02 – 7.37)	0.501
Unprotected sex with PWID – n(%)	8 (8.6)	5 (6.9)	0.49 (0.10 – 2.33)	0.371
Snorted drugs (past 30 days) – n(%)	53 (57.0)	38 (52.8)	0.67 (0.30 – 1.51)	0.337
Network characteristics (n=145)g
Number of injection partners – mean (SD)	0.11 (0.52)	0.15 (0.81)	1.18 (0.69 – 2.01)	0.539
Number of people in personal network who inject – mean (SD)	0.29 (0.80)	0.29 (0.91)	1.04 (0.67 – 1.60)	0.878
Number of people to whom participant talks about injection-related risk reduction – mean (SD)	0.27 (0.94)	0.16 (0.55)	0.73 (0.38 – 1.37)	0.325
Frequency of sharing injection equipment with all network members – mean (SD)	0.14 (0.83)	0.35 (2.16)	1.01 (0.70 – 1.47)	0.954
Number of people with whom participant uses drugs – mean (SD)	1.46 (1.79)	1.10 (1.31)	0.87 (0.66 – 1.15)	0.334
Total frequency of drug sharing with all partners – mean (SD)	3.94 (5.19)	2.71 (3.28)	0.94 (0.84 – 1.04)	0.234
Number of network members providing social support – mean (SD)	1.75 (1.32)	1.85 (1.32)	1.05 (0.76 – 1.46)	0.768
Number of network members providing financial support – mean (SD)	0.59 (0.73)	0.95 (1.02)	1.75 (1.01 – 3.03)	0.047*

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 266 participants who were already HCV positive (confirmed using OraQuick Rapid HCV tests) and two additional participants who were prompted to skip WTP questions when they self-reported being HCV positive although confirmatory testing had not yet been performed

^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

^g20 participants reported no network members