“…There is ample evidence that ED crowding can be reduced by hospital-wide 6,7 and system-wide 8,9 interventions and some evidence of resultant improvement in patient outcomes including mortality. [10][11][12] There are conflicting reports on whether reducing patient time in the ED is associated with increased return visits 7,9,10 and there is evidence for an optimal level of short ED times. 13 In Australia, much of the recent evidence was derived during the period of Western Australia's '4 h rule' driven by a single State Health Department and the nationwide 'National Emergency Access Target' (NEAT).…”