Evaluating networked drug checking services in Toronto, Ontario: study protocol and rationale.

BACKGROUND: The increasing incidence of fatal opioid overdose is a public health crisis in Canada. Given growing consensus that this crisis is related to the presence of highly potent opioid adulterants (e.g., fentanyl) in the unregulated drug supply, drug checking services (DCS) have emerged as part of a comprehensive approach to overdose prevention. In Canada's largest city, Toronto, a network of DCS launched in 2019 to prevent overdose and overdose-related risk behaviors. This network employs mass spectrometry technologies, with intake sites co-located with supervised consumption services (SCS) at three frontline harm reduction agencies. The protocol and rationale for assessing the impact of this multi-site DCS network in Toronto is described herein. The aims of this study are to (1) evaluate the impact of DCS access on changes in and factors influencing overdose and related risk behaviors, (2) investigate the perceived capacity of DCS to prevent overdose, and (3) identify composition (qualitative and quantitative) trends in Toronto's unregulated drug supply. METHODS: We will use a parallel-mixed-methods design with complementary data sources (including data from chemical analysis of drug samples, quantitative intake and post-test surveys, SCS, coroners, paramedic services, and qualitative interviews), followed by a meta-inference process wherein results from analyses are synthesized. RESULTS: Whereas most DCS globally target "recreational drug users," in Toronto, this networked DCS will primarily target marginalized people who use drugs accessing frontline services, many of whom use drugs regularly and by injection. This evolution in the application of DCS poses important questions that have not yet been explored, including optimal service delivery models and technologies, as well as unique barriers for this population. Increasing information on the unregulated drug supply may modify the risk environment for this population of people who use drugs. CONCLUSIONS: This study addresses evidence gaps on the emerging continuum of overdose prevention responses and will generate critical evidence on a novel approach to reducing the ongoing high incidence of drug-related morbidity and mortality in Canada and elsewhere.

Interrupting the social processes linked with initiation of injection drug use: results from a pilot study.

BACKGROUND: Injection drug use is a skill learned in social settings. Change the Cycle (CTC), a peer-delivered, one-session intervention, is designed to reduce among people who inject drugs (PIDs) injection initiation-related behaviours (i.e., speaking positively about injecting to non-injectors, injecting in front of non-injectors, explaining or showing a non-injector how to inject) and initiation of non-injectors. We hypothesized that participation in CTC would lead to reductions in initiation-related behaviours six months later. METHODS: Using respondent driven sampling (RDS), 98 PIDs were recruited in Toronto, Canada to participate in pilot testing of CTC. The baseline session consisted of a structured interview, the peer-delivered CTC intervention, instructions regarding RDS coupon distribution, and an invitation to return in six months for a follow-up interview. For the 84 PIDs completing the six-month interview, we compared initiation-related behaviours at baseline with six-month follow-up. RESULTS: The proportion of PIDs offering to initiate a non-injector was reduced from 8.4% (95% CI: 2.5, 15.9) at baseline to 1.59% (95% CI: 0.4, 3.7) at 6-month follow-up. The prevalence of speaking positively about injection to non-injectors also decreased significantly. The proportion of PIDs who helped a non-injector with a first injection at baseline was 6.2% (95% CI: 2.1, 11.3) and at follow-up was 3.5% (95% CI: 0.8, 7.1). Paired analyses of initiator baseline versus follow-up data showed a 72.7% reduction in initiation (95%CI: 47.7, 83.1). CONCLUSIONS: While further refinements remain to be tested, pilot study results suggest that CTC holds promise as a prevention intervention.