AbstractBackgroundThere is a growing body of literature relating to mass-gathering events. A common thread amongst this literature, particularly the literature relating to music festivals, is the incidence of patients presenting with substance and/or alcohol intoxication. However, the impact of alcohol and/or drugs on the provision of in-event health care services has not been explored in detail.AimThe goal of this review was to develop an understanding of the impact of alcohol and/or drugs on in-event health care services at mass-gathering events.MethodThis paper used integrative review as a methodology. The articles included in this literature review were sourced by searching databases inclusive of Medline (Ovid; US National Library of Medicine, National Institutes of Health; Bethesda, Maryland USA), Scopus (Elsevier; Amsterdam, Netherlands), PsycINFO (Ovid; American Psychological Association; Washington DC, USA), and Pub Med (National Center for Biotechnology Information, National Institutes of Health; Bethesda, Maryland USA). Identified manuscripts that met the inclusion criteria were thematically analyzed.ResultsIn total, 12 manuscripts met the inclusion criteria for this review. A thematic analysis of these manuscripts identified three main themes: (i) predictive factors, (ii) patient presentation rates, and (iii) levels of care.Conclusion:Substance use and/or intoxication can place a strain on in-event medical services at mass-gathering events. Of the various types of mass-gathering events, music festivals appear to be the most affected by substance use and intoxication.BullockM, RanseJ, HuttonA.Impact of patients presenting with alcohol and/or drug intoxication on in-event health care services at mass-gathering events: an integrative literature review. Prehosp Disaster Med. 2018;33(5):539–542.