Comparing heroin users and prescription opioid users in a Canadian multi-site population of illicit opioid users.

Introduction And Aims: Recent data suggest increasing prescription opioid and decreasing heroin use among street drug users, yet little is known on possible differential use characteristics and outcomes associated with these drugs. [While we recognise that, correctly, these populations would need to be labelled as opioid 'abusers' or 'non-medical users', we rely on the simpler terms 'use' and 'users' for the population under study within the wider context of them being engaged overall in illicit opioid use activities.] This study compared drug use, health, and socio-economic characteristics between heroin (H)-only, prescription opioid (PO)-only and mixed heroin and prescription (PO & H) users in a Canadian multi-site cohort of illicit opioid and other drug users (OPICAN).

Design And Methods: Data from the most recent (2005) multi-component assessment of the H-only (n = 94), PO-only (n = 304) and PO & H (n = 86) cohort sub-samples were analysed. Based on bivariate analyses of variables of interest, a multinomial logistic regression analysis (MLRA) model was computed, comparing PO-only and PO & H groups to the H-only reference group, respectively.

Results: H-only users were found in two of the seven study sites. Based on the MLRA, PO-only and PO & H users, compared to H-only users, were more likely to: be older, use benzodiazepines and cocaine, use drop-in shelters and less likely to use walk-in clinics. PO-only users were also more likely to: be white; receive legal income; use drugs by non-injection; have physical health problems; and use private physician services.

Discussion And Conclusions: Our study underscores the increasing prevalence of PO compared to heroin use in the study population. Differences between PO-only and H-only users were more pronounced than differences between PO-only and PO & H users. PO-only use may be associated with lowered health risks and social burdens, yet concerns regarding polysubstance use and drug sourcing arise. Challenges for targeted interventions are discussed.