Kim, JulieKwok, EdmundCook, OliviaCalder, Lisa2019-03-262019-03-2620181936900Xhttps://doi.org/10.20381/ruor-23189http://hdl.handle.net/10393/38939Highly frequent users (HFU) of the emergency department (ED) are a poorly defined population. This study describes patient and visit characteristics for Canadian ED HFU and patient subgroups with mental illness, substance misuse, or ≥ 30 yearly ED visits.enAbdominal PainAdolescentAdultAgedAged, 80 and overAlcoholic IntoxicationEmergency Service, HospitalFemaleHumansMaleMiddle AgedMusculoskeletal PainOntarioRetrospective StudiesYoung AdultTriageArticle10.5811/westjem.2018.9.39369