Baseline characteristics of people who inject drugs enrolled in the Montreal Hepatitis C Cohort (2004–2017), by prescribed dosage of opioid agonist treatment, categorized according to clinical guideline recommendations* and patient-perceived dosage adequacy
| Characteristic | Dosage of opioid agonist treatment and perceived adequacy; no. (%) of participants† | p value‡ | ||||
|---|---|---|---|---|---|---|
| Not enrolled in opioid agonist treatment n = 354 | High dosage, perceived adequate n = 61 | High dosage, perceived inadequate n = 25 | Low dosage, perceived adequate n = 49 | Low dosage, perceived inadequate n = 24 | ||
| Age, yr, mean (± SD) | 35.8 (± 10.8) | 39.5 (± 10.7) | 38.4 (± 9.6) | 34.9 (± 9.7) | 32.3 (± 7.9) | 0.02 |
| Age, yr, median (IQR) | 33.9 (26.9–44.3) | 40.7 (31.1–47.3) | 37.5 (32.2–43.0) | 33.3 (27.4–42.3) | 31.3 (26.7–35.6) | 0.03 |
| Sex, male | 284 (80.2) | 43 (70.5) | 16 (64.0) | 36 (73.5) | 19 (79.2) | 0.3 |
| College education or higher | 74 (20.9) | 22 (36.1) | 10 (40.0) | 13 (26.5) | 11 (45.8) | < 0.01 |
| Duration of injection drug use, yr, mean (± SD) | 11.0 (± 10.2) | 18.2 (± 9.4) | 16.5 (± 11.5) | 13.4 (± 9.9) | 11.6 (± 8.8) | < 0.01 |
| Duration of injection drug use, yr, median (IQR) | 7.8 (2.8–16.2) | 18.0 (10.1–26.1) | 15.0 (4.7–25.0) | 12.3 (4.6–20.3) | 9.7 (4.0–16.1) | < 0.01 |
| Opioids injection, past mo | 260 (73.4) | 33 (54.1) | 22 (88.0) | 37 (75.5) | 22 (91.7) | < 0.01 |
| Cocaine injection, past mo | 191 (54.0) | 28 (45.9) | 8 (32.0) | 25 (51.0) | 11 (45.8) | < 0.01 |
| High frequency of injection drug use (≥ 30 injections), past mo | 208 (58.8) | 20 (32.8) | 13 (52.0) | 22 (44.9) | 19 (79.2) | < 0.01 |
| Unstable housing, past mo | 147 (41.5) | 16 (26.2) | 4 (16.0) | 8 (16.3) | 7 (29.2) | < 0.01 |
| Incarceration, past 3 or 6 mo§ | 76 (21.5) | 12 (19.7) | 5 (20.0) | 9 (18.4) | 7 (29.2) | 0.9 |
| Previous HCV infection | 76 (21.5) | 34 (55.7) | 14 (56.0) | 25 (51.0) | 9 (37.5) | < 0.01 |
| 2004–2011 follow-up wave (v. 2011–2017) | 199 (56.2) | 21 (34.4) | 12 (48.0) | 27 (55.1) | 10 (41.7) | 0.02 |
Note: HCV = hepatitis C virus, IQR = interquartile range, SD = standard deviation.
↵* Prescribed dosage was categorized as high if methadone ≥ 60 mg/d or buprenorphine ≥ 16 mg/d, and low otherwise.3,5–7
↵† Unless stated otherwise.
↵‡ p value derived from analysis of variance and Kruskal–Wallis test for age and duration of injection, and χ2 test for all other variables.
↵§ Depending on follow-up wave.