Scoping reviews are a variant of knowledge synthesis, using a systematic approach to map evidence on a topic and identify key concepts, theories, sources, and knowledge gaps [27]. Scoping reviews address broader questions than systematic reviews and are usually conducted to identify gaps in knowledge; examine the extent (i.e. size), range (i.e. variety) and nature (i.e. characteristics) of the evidence on a certain topic or question; summarize findings from a body of knowledge that is heterogeneous in methods or discipline or set agendas for future research [27].
This scoping review will be conducted by 11 individuals: 10 researchers from sev- eral universities worldwide, from a range of disciplines (e.g. public health, economics, epidemiology, and pharmacy), and an informationist from the Harvey Cushing/John Hay Whitney Medical Library at Yale University. Two team members will review articles, facilitated by the informationist. Remaining team members will provide oversight of results write-up. We chose to conduct a scoping review due to: 1) Scop- ing reviews are appropriate for broad research questions such as ours, i.e. mapping an area of research [28]; 2) substance use and SUD research outcomes are not suffi- ciently similar to warrant pooling or formal meta-analysis; 3) We are not examining the effect of an intervention on an outcome of interest, as per a systematic review [29].
Research objectives, inclusion criteria, and methodological techniques were deter- mined before study commencement using the Joanna Briggs Institute Reviewers’
Manual 2015 Methodology for JBI Scoping Reviews [30]. This process will adhere to the indicated framework: 1) identifying research question; 2) identifying relevant studies; 3) developing comprehensive search strategy; 4) selecting studies; 5) chart- ing data; and 6) collating, summarizing and reporting results. The objective of the scoping review is to develop a better understanding of the current research landscape around substance use and SUD, in relation to COVID-19 by investigating existing studies and gaps in the research. The broad research questions are “What does cur- rent research suggest about the impact of substance use and SUDs on COVID-19 infection and progression?” and “What impact has COVID-19 had on substance use and SUD rates?” The search strategy will be performed in line with techniques that enhance methodological transparency and improve the reproducibility of the results and evidence synthesis. The study team will develop a search strategy as recommended by the 2015 Methodology for JBI Scoping Reviews. Reporting of re- sults will conform to PRISMA Extension for Scoping Reviews (PRISMA-ScR) [31]. See supplement for PRISMA-ScR checklist.
Search method
Studies will be reviewed across 15 databases: Cumulative Index to Nursing and Allied Health Literature, China National Knowledge Infrastructure, Africa-Wide Information, Web of Science Core Collection, Embase, Global Health, WHO Global Literature on Coronavirus Disease Database, WHO Global Index Medi- cus, PsycINFO, PubMed, Al Manhal, Middle Eastern Central Asian Studies, Arab World Research Source, CINAHL Complete, and Sociological Abstracts. To achieve good coverage of preprint servers, we will search EuropePMC’s preprint collection, which currently indexes content from preprint servers including bioRxiv, medRxiv, F1000, PeerJ Preprints, and Research Square; we will also search PsyArXiv. We will have no language restrictions for searches.
We will search the literature from January 2020 (COVID-19 report to the World Health Organization) until September 2020 [32]. We may extend the end date for the literature search. We will also conduct a grey literature search using Disaster Lit, HSRProj, Google Scholar, governmental websites and clinical trials registries (e.g. ClinicalTrial.gov, World Health Organization International Clinical Trials Reg- istry Platform and International Standard Randomized Controlled Trial Number registry). We will use search terms similar to our main search to find articles for inclusion. All grey literature will be compiled in a folder and reviewed similarly to articles obtained from our database searches. EndNote, a bibliographic soft- ware, will be used to store, organize, and manage all references [33]. This allows cross-monitoring of data records and removal of duplicates. Covidence will be used to manage the title/abstract and full-text screening phases [34]. Reference lists in reports, investigative news articles, journal papers and academic theses will also manually searched by the team to identify any additional relevant literature not captured.
Study selection criteria
We will include all studies with all study designs involving COVID-19, substance use and SUD, inclusive of all variants of substance use, such as alcohol, tobacco, nicotine,
cannabis/marijuana, and opioids, and all substance use disorders (e.g. opioid use disorder, cannabis use disorder, alcohol use disorder). We will include studies that investigate substance use as a predictive factor for COVID-19 diagnosis/severity, and research about substance use treatment during the pandemic. We will include research that explores the relationship between COVID-19 public health interven- tions (e.g. lockdowns), and substance use and SUD. Two independent reviewers in the study team will screen each title and abstract as per inclusion/exclusion criteria (see below). Disagreements between reviewers will be resolved by a third reviewer.
Inclusion criteria
No language restrictions.
Research (grey literature included) investigating substance use and SUD, in relation to COVID-19 in all populations and settings.
All variants of substance use disorder will be included, such as opioid use disorder, cannabis use disorder, alcohol use disorder.
All variants of substance use, smokable or otherwise, will be included, such as al- cohol, tobacco, nicotine, cannabis, cocaine, methamphetamine, non-medical use of psychoactive prescription drugs, and opioids.
There will be no restrictions on age, region, and gender.
All study designs - original research only, e.g. quantitative and qualitative studies, will be included.
Exclusion criteria
Commentaries, correspondences, case reports, case series, editorials, and opinion pieces will be excluded.
Governmental or other agency guidelines will be excluded.
Study selection
Reviewers will be trained in calibration and will utilize standardized screening forms. Reviewers will independently screen all titles and abstracts that we iden- tify through the literature search strategy. We will obtain full-text articles of all possibly eligible studies and evaluate article eligibility. Reviewers will resolve dis- agreement around eligibility by discussion, or if necessary, with a third reviewer. Studies reported only as conference abstracts will be included. Conference abstracts are often left out of systematic reviews as they may not contain adequate informa- tion. Here, we will include conference abstracts as they are often published earlier than full manuscripts [35], which is key to a thorough scoping review on an ongo- ing phenomenon. We will contact authors where necessary if the abstracts do not provide sufficient information [35].
Data extraction
Reviewers will undergo practice exercises and then independently extract data from studies. An inter-rater agreement pilot will be done to make sure that the inclu- sion/exclusion criteria are clear, and that agreement is acceptable between the two
reviewers [27]. Reviewers will abstract the data using a pretested data extraction template. We will use a standardized coding protocol to collect information such as: title of study with all author information and month/year published; study set- ting; study design; description of methodology; description of study sample; type of substance studied (if applicable); measurements and scales used; main findings; funder information.
Descriptive analysis
A narrative synthesis of the outcomes and other information collected regarding se- lected studies will be detailed in the final review. The broad goal of the synthesis is to map the research published to date, identify gaps in research, and present recom- mendations for future research agendas. We will also provide a critical assessment of methodological issues in the current literature, and ways to address them.
Amendments
Any amendments to this protocol will be documented with reference to saved searches and analysis.
Dissemination
Results of the review will be disseminated in a peer-reviewed journal and likely in other media such as: conferences, seminars, symposia. As per PRISMA-ScR guide- lines, we will present results in a user-friendly format [36].