Table 1.
Factors associated with willingness to participate in an HIV vaccine trial among HIV-positive injection drug users (n=75)
| Variable | WTP (n=46) n (%) |
not WTP (n=29) n (%) |
p-value* |
|---|---|---|---|
| Sociodemographics | |||
| Age mean (median) (IQR)** |
42.3 years (43.7) (35.6–48.0) |
41.7 years (43.1) (36.9–46.9) |
0.76* (t-test) |
| Female (reference) Male |
19 (41) 27 (59) |
13 (45) 16 (55) |
0.76 |
| Aboriginal ethnicity*** | 20 (43) | 16 (55) | 0.32 |
| Education ≥ high school | 24 (52) | 13 (45) | 0.54 |
| Employment | 9 (20) | 4 (14) | 0.76¥ |
| Unstable Housing† | 37 (80) | 21 (72) | 0.42 |
| Drug use & risk variables | |||
| Borrowed needles† | 2 (4) | 1 (3) | 1.00¥ |
| Lent needles† | 1 (2) | 0 | 1.00¥ |
| Injection heroin ≥daily‡ | 9 (20) | 7 (24) | 0.64 |
| Injection cocaine ≥ daily‡ | 5 (11) | 2 (7) | 0.70¥ |
| Smoking crack ≥ daily‡ | 25 (54) | 9 (31) | 0.05 |
| Sex trade involvement† | 4 (9) | 5 (17) | 0.30¥ |
| Incarceration† | 7 (15) | 2 (7) | 0.47¥ |
| Health Service and Utilization | |||
| Attended NEP (ever vs. never) | 34 (74) | 16 (55) | 0.09 |
| NEP ≥ 1/week | 17 (37) | 10 (34) | 0.83 |
| Injecting in Insite (ever vs. never | 34 (74) | 19 (66) | 0.44 |
| Injecting in Insite† | 24 (52) | 13 (45) | 0.54 |
| Drug / alcohol treatment† | 23 (50) | 15 (52) | 0.88 |
| Psychosocial Variables | |||
| Depression (≥ 16)§ (n = 62) |
26 (67) (n=39) |
14 (61) (n=23) |
0.65 |
| Cognitive Factors | |||
| Treatment optimism | |||
| By taking HIV medicines, an HIV+ person reduces the chance of infecting someone with HIV through sharing needles▪ | 0.73 | ||
| By taking HIV medicines, an HIV+ person reduces the chance of infecting someone with HIV through unprotected sex▪ | 0.74 | ||
| Treatment optimism sum | 0.95 | ||
| Knowledge Questions Correct vs. Incorrect / Don’t know (Question) | |||
| 1 | 12 (26) | 10 (34) | 0.44 |
| 2 | 11 (24) | 8 (28) | 0.72 |
| 3 | 16 (33) | 13 (45) | 0.38 |
| 4 | 24 (52) | 16 (55) | 0.80 |
| 5 | 4 (8) | 9 (31) | 0.03¥ |
| 6 | 25 (51) | 12 (41) | 0.28 |
| 7 | 13 (27) | 13 (45) | 0.14 |
| 8 | 17 (35) | 13 (45) | 0.50 |
| 9 | 18 (39) | 13 (45) | 0.63 |
| 10 | 39 (85) | 19 (66) | 0.05 |
| Knowledge sum (items 1–10) | 0.41 (t-test) |
||
| HAART treatment | 29 (63) | 20 (69) | 0.60 |
Notes: NEP, needle-exchange program; HAART, highly active antiretroviral therapy.
*
Two-tailed probability.
**
IQR, Interquartile range
***
First Nations (native), Metis, or Inuit.
†
Activities in the last 6 months.
‡
Current activities.
¥
Fisher’s exact test.
§
Center for Epidemiologic Studies Depression Scale (CES-D) (20 item 4-point scale) standard cut-off score of ≥ 16.
▪
5-point optimism scale ranging from “strongly disagree” to “strongly agree”.