Sustainable harm reduction needle and syringe programs for people who inject drugs: A scoping review of their implementation qualities

While substance use disorders (SUD) continue to be a global concern, harm reduction approaches can provide sustainable harm minimization to people who inject drugs (PWID) without requiring abstinence. Yet, the evidence for the sustainable implementation of harm reduction approaches is newly emerging. This scoping review sought to map the evidence on implementation qualities of sustainable harm reduction needle and syringe programs (NSPs). We searched the Cochrane Database of Systematic Reviews, PubMed, ProQuest Central, and Directory of Open Access Journals for empirical studies (a) with an explicit focus on harm minimization NSPs, (b) with a clearly identified study population, (c) that described the specific NSP implementation protocol, (d) that provided information on accessibility, affordability, and feasibility, and (e) were published in English between 2000–2020. Following narrative qualitative synthesis, the evidence suggests individual implementer characteristics directly influenced sustainable availability and scope of NSP provision while implementation processes explained the predictability and continuity of service provision across services. External factors including community perceptions of NSPs and policing activity influenced the sustainability of NSP implementation. The emerging evidence suggests that sustainable NSP programs for PWID require provider, consumer, and community engagement, supported by enabling health policies.