Theme: Epidemiology & Public Health Research Year: 2017
Background: Although opiate agonist therapy (OAT) is considered key in hepatitis C virus (HCV) prevention among people who inject drugs (PWID), whether access is similar among those using heroin and prescription opioids (PO) is unclear. The aim of this study was to compare rates of OAT initiation among PWID according to preferred opioid of abuse (PO vs heroin).
Methods: Data were drawn from HEPCO, a prospective cohort study of PWID in Montreal, Canada, between 2004 and 2011. Participants were followed at six-month intervals to collect information on socio-demographics, drug use behaviours and OAT initiation. For this study, participants were eligible if they indicated at baseline their preferred drug of abuse to be heroin or PO, did not receive OAT in the past six months, and were followed-up at least once. Incidence rates of first OAT initiation during follow-up were calculated using the person-time method.
Results: 128 PWID were eligible for this analysis, and contributed 125.6 person-years (p-y) of follow-up. At baseline assessment, relative to those preferring heroin (n=72 (56.2%), those who prefer PO (n=56 (43.8%)) were more likely to be older (mean age: 32.6 vs 30.2), of male gender (83.9% vs 72.2%), also use cocaine (57.1% vs 44.4%) and sedatives (56.4% vs 32.4%), and to live in unstable housing conditions (60.7% vs 31.9%). PWID indicating their preferred drug to be PO had a lower rate of OAT initiation relative to those indicating heroin [incidence rates: 41.3 per 100 p-y (95% confidence interval (CI): 29.1–54.4) vs 71.5 per 100 p-y (95% CI: 58.7–82.2)].
Conclusion: Findings suggest that PWID whose drug of choice is PO are less likely to initiate OAT compared to those preferring heroin. This group presents characteristics potentially placing them at greater risk of HCV infection. Targeted efforts are needed to engage PO users in addiction treatment.
Download abstract