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UBC Theses and Dissertations

Injection career trajectories among illicit drug users in Vancouver, Canada Werb, Dan


Background: Though vast resources have been allocated toward the prevention of illicit drug use, the prevalence of injection drug use remains high globally. This thesis therefore sought to identify factors that influence the natural history of injection drug use by: systematically reviewing the epidemiologic literature on the prevention of injecting initiation; identifying the role of drug-related and personality-based risk factors in increasing the risk of injecting initiation; and evaluating the role of harm reduction interventions in potentially modifying the likelihood of injecting cessation among injection drug users (IDU). Methods: Street-involved youth and IDU participating in ongoing prospective observational cohorts in Vancouver, Canada, completed semi-annual interviewer-administered questionnaires. Longitudinal epidemiologic methods were applied to assess the association between selected drug-related, personality-based (e.g., sensation seeking level), and structural factors on the outcomes of interest, while controlling for a variety of potential sociodemographic and behavioural confounders. Results: The systematic review found that a limited set of interventions to prevent injecting has been scientifically evaluated and implemented. A longitudinal analysis of injecting initiation found that non-injection crystal methamphetamine use was significantly associated with injecting initiation among street-involved youth. The adaptation of a sensation seeking scale for use in a related longitudinal analysis found that higher sensation seeking was associated with injecting and risk factors for injection initiation. Finally, in a longitudinal analysis conducted over a span of 15 years, rates of injecting cessation among a cohort of IDU increased significantly despite a substantial expansion in needle and syringe program (NSP) implementation. Conclusions: This thesis identified gaps in current responses to preventing injection drug use. A set of drug-related and personality-based factors associated with increased risk of injecting initiation among street-involved youth was also identified, including non-injection crystal methamphetamine use and higher sensation seeking. Further, an increase in the rate of injecting cessation among IDU occurred during a period of substantial expansion of NSP sites in Vancouver. These results suggest that resources should be allocated towards the development of interventions to prevent injection initiation, and that harm reduction interventions should be considered complementary to broader efforts to reduce both injection drug use and related harms.

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Attribution-NonCommercial-NoDerivs 2.5 Canada