The Implementation of Drug Checking Services for People Who Use Drugs: A Systematic Review

Background and Aims: Drug checking services (DCS) provide people who use drugs (PWUD) with chemical analysis results of their drug samples, while simultaneously monitoring the unregulated drug market. We sought to identify and synthesize literature on the following domains: (a) influence of DCS on behaviour of PWUD; (b) monitoring of drug markets by DCS; and (c) outcomes related to models of DCS. Methods: This review followed PRISMA guidelines and was pre-registered in PROSPERO (CRD42018105366). A systematic literature search was conducted in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PsycINFO, Scopus, Web of Science, and Dissertations & Theses Global. Eligible studies were peer-reviewed articles and conference abstracts, or grey literature, published in any language since 1990 and including original data on the domains. We assessed risk of bias for quantitative peer-reviewed articles reporting on behaviour or models of DCS using National Institutes of Health tools. Results: We screened 2,463 titles and abstracts and 156 full-texts, with 90 studies meeting inclusion criteria. Most (n=65, 72.2%) were from Europe and used cross-sectional designs (n=79, 87.7%). Monitoring of drug markets by DCS (n=63, 70%) was most commonly reported, followed by influence of DCS on behaviour (n=31, 34.4%) and outcomes related to models of DCS (n=17, 18.9%). The most common outcome measures were detection of unexpected substances (n=50, 55.6%), expected substances (n=44, 48.9%), new psychoactive substances (n=40, 44.4%), and drugs of concern (n=32, 36.5%) by DCS. Conclusions: Monitoring of drug markets by DCS is well established in Europe and increasingly in North America. There is an emerging evidence base demonstrating the capacity of DCS to influence behavioural intention, and a smaller subset of findings on its impact on the enacted behaviour of PWUD. Further research is needed on enacted behaviours and corresponding health outcomes including overdose, particularly among people who inject drugs or use Qeios, CC-BY 4.0 · Article, April 30, 2021 Qeios ID: TXE86U · https://doi.org/10.32388/TXE86U 1/44


DISCUSSION
This systematic review identified 90 studies evaluating the impacts of DCS from 1990-2019. While scholarship is growing, knowledge gaps persist. Studies evaluating DCS were overwhelmingly geographically concentrated in Europe (72.2%).
Given most European DCS target PWUD in party settings, the available evidence on DCS is largely focused on this subpopulation. While these findings may not be generalizable (97) -particularly to different subpopulations of PWUDrecent expansion of DCS for overdose prevention in Canada and the US has led to an emergent evidence base on the impact of DCS on structurally vulnerable PWUD.
Monitoring of drug markets by DCS was the predominant domain reported in the literature. Strong evidence exists demonstrating that DCS provide a unique form of drug market monitoring by providing information on the level of concordance between expected (i.e., anticipated by individuals accessing DCS) and detected contents in drug samples. Available evidence also demonstrates the capacity of DCS to detect NPS and drugs of concern. Our primary domain -the influence of DCS on behaviour of PWUD -was measured in a third of studies, while behavioural intention in response to analysis results from DCS was assessed most often (24.4%). Adjustments in behaviour were found across reporting studies, and were generally more common when results from DCS were unexpected or drugs of concern.
Given the proliferation of DCS since 1992 in non-English speaking countries, the comprehensiveness of this systematic review is a key strength achieved through inclusion of studies since 1990 in all languages, grey literature, and peerreviewed conference abstracts. This work has limitations, however, typical of systematic reviews. Publication bias may limit the representativeness of the included literature, as studies not showing positive impacts of DCS could be underrepresented. In addition, due to resource limitations, we only reviewed grey literature on the primary domain and did not appraise the quality of grey literature or qualitative studies. Studies for which quality was assessed were not of high quality, which may increase the level of uncertainty with respect to outcomes reported. Key methodological limitations among studies reporting on behaviour of PWUD include cross-sectional designs and behavioural intention measures subject to the intention-behaviour gap (98). Challenges facing the generation of evidence on DCS include limited resources for research and evaluation as well as barriers to conducting research on PWUD and DCS due to drug criminalization (99).

Conclusions
This systematic review found that monitoring of drug markets by DCS is well established in Europe and increasingly in North America, and there is an emerging evidence base on the capacity of DCS to influence behavioural intention, and to a lesser extent, enacted behaviour, among PWUD. Further research on enacted behaviours, linking behaviours to health outcomes, and among people who inject drugs or use opioids would benefit the knowledge base, as would more rigorous and higher quality study designs. As DCS gain popularity, ongoing scientific evaluations across settings are critical to understanding the impact and limitations of this intervention.        TOPIC: (kosmicare OR "drug test strip*" OR knowyourstuffnz OR "Servicio de Analisis de Sustancias" OR "ACT Investigation of Novel Substances Project" OR "Lonja Laket Project" OR drugsdata OR ecstasydata OR drogart OR "Modus Fiesta" OR technoplus OR sintes OR raveitsafe* OR saferparty* OR dancesafe* OR "adulterant screening" OR "street drug test*" OR "street drug analysis" OR "Trans European Drug Information" OR "drug information and monitoring system" OR checkit! OR "drug test* kits" OR "drug test* kit" OR "pill testing" OR "pill checking" OR "drug test* check*" OR "drug test* information" OR "drug test* service" OR "drug checking")

Dissertations & Theses Global
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