PROTOCOL Open Access Interventions to improve emergency department use for mental health reasons: protocol for a mixed-methods systematic review Amanda Digel Vandyk 1* , Mark Kaluzienski 2 , Catherine Goldie 3 , Yehudis Stokes 1 , Amanda Ross-White 4 , Jeremy Kronick 5 , Matthew Gilmour 6 , Colleen MacPhee 7,8 and Ian D. Graham 9,10 Abstract Background: Healthcare resources are limited and unnecessary, and inappropriate emergency department use is now a highly visible healthcare priority. Individuals visiting the emergency department for mental health-related reasons are often amongst the most frequent presenters. In response, researchers and clinicians have created interventions to streamline emergency department use and several primary studies describe the effects of these interventions. Yet, no consensus exists on the optimal approach, and information on the quality of development, effectiveness, acceptability, and economic considerations is hard to find. The purpose of this study is to systematically review interventions designed to improve appropriate use of the emergency department for mental health reasons. Method: A mixed-method systematic review using Joanna Briggs Methodology. Search combining electronic databases (EMBASE, MEDLINE, PsycINFO, CINAHL, HealthSTAR, PROQUEST, Cumulative Index to Nursing and Allied Health) and secondary searches (grey literature and hand search with consultation). Two independent reviewers will screen titles and abstracts using predetermined eligibility criteria and a third reviewer will resolve conflicts. Full texts will also be screened by two independent reviews and conflicts resolved in a consensus meeting with a third reviewer. A pilot-tested data extraction form will be used to retrieve data relevant to the study objectives. We will assess the quality and of all included studies. Data describing interventions will be summarized using logic models and reported narratively. Quality of development will be assessed using the Oxford Implementation Index. For data on intervention effectiveness, we will assess statistical heterogeneity and conduct a meta-analysis using a random effects method, if appropriate. For interventions that cannot be pooled, we will report outcomes narratively and descriptively. Qualitative data on acceptability will be synthesized using meta-aggregation and an economic evaluation of interventions will be done. The reporting of this protocol follows the PRISMA-P statement. Discussion: Using a combined systematic review methodology and integrated knowledge translation plan, the project will provide decision makers with concrete evidence to support the implementation and evaluation of interventions to improve emergency department use for mental health reasons. These interventions reflect widespread priorities in the area of mental health care. Systematic review registration: PROSPERO CRD42018087430 Keywords: Psychiatry/mental health, Emergency department use, Interventions, Systematic review, Mixed-methods © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. * Correspondence: avandyk@uottawa.ca 1 School of Nursing, Faculty of Health Sciences, University of Ottawa, Ottawa, Canada Full list of author information is available at the end of the article Vandyk et al. Systematic Reviews (2019) 8:84 https://doi.org/10.1186/s13643-019-1008-6