In the 23 primary studies included in this report, the majority of the strategies addressed the contributing factors within the ED, with very little research focusing on strategies in the domain of community. [...] Reasons for ED use by non-urgent patients were either financial or related to access to care,30 which may include: (1) proximity to the ED, (2) social deprivation, (3) the inability to gain access to general practitioner services, (4) a poor knowledge of general practitioner services, (5) the convenience of 24-hour service of the ED, (6) the perceived urgency of the complaint, and (7) the perceive [...] The number of patients boarded in the ED is considered one of the most important determinants of ambulance diversion. [...] A variety of outcome timing measurements were utilized, including the interval from arrival to triage, from triage to seeing the doctor or nurse practitioner, from arrival to seeing the doctor or nurse practitioner, from the decision to admit to departure from the ED, and from arrival to departure time from the ED, as well as ambulance diversion. [...] This systematic review concluded the following: Despite the general limitations of the research, some evidence was available for the effectiveness of restricted ED access and expanded access to primary care and the efficacy of cost sharing, which have consistently been found to be effective methods to restrict ED use.