Mass gathering public health and emergency medicine literature review: Levels of evidence

Background The science of mass gatherings is a relatively new and developing field. It is currently at a stage where summarising the rigour of knowledge gained about the complex interrelationships between key characteristics of an event, spectator profiles and health implications are critical. This study seeks to summarise the levels of evidence in peer-reviewed journal articles concerning mass gathering public health and emergency medicine published 2001 to 2011. Until now, the evidence behind the science of mass gathering public health and emergency medicine has not been critically analysed. Methods Publications were reviewed by searching the following online databases: GALE, NLM, Web of Science, Elsevier, Wiley, BMJ Journals, OUP, IngentaConnect, RMIT, DOAJ and JSTOR. Published news articles and grey literature were omitted. The peer-reviewed articles were organised into pre-determined World Health Organisation categories and the levels of evidence were assessed using the effectiveness classifications developed by the Joanna Briggs Institute. Descriptive statistical analysis was then undertaken using Microsoft Excel®. Results Of all publications examined, 38!86% (n = 89) of the articles found in this review were categorised as observational studies, 36!68% (n = 84) were expert opinion or consensus, 20!09% (n = 46) were cohort studies, 2!18% (n = 5) were case-controlled studies and 2!18% (n = 5) were quasi-experimental studies. Conclusion High-level evidence studies may not be possible in the mass gathering context, but research in the middlelevel should be encouraged to ensure that literature is less reliant on experience and expert opinion when applied to event management strategies which impact on public health and emergency medicine.