Ambulance diversionWhere ambulances are diverted to another emergency department (ED) from the one they would normally have gone to under normal circumstances
Access blockAccess to hospital beds is blocked, meaning that patients cannot be admitted to them. The term ‘exit block’ is synonymous
Assessment unitTypically medical, surgical, paediatric case mix. Usually run by inpatient teams as short stay assessment and treatment areas for their admitted patients
BoardingPatients are deemed to need admission to hospital, but there is no bed for them to be transferred to. They are said to be boarding in the ED
CensusHead count of either number of patients presenting to an ED over a given time period (eg, annual census), or number of patients in the ED itself at a given point in time
Left without being seenLeft without being seen (LWBS)/left without treatment (LWT)/did not wait (DNW): when patients choose to leave the ED before their care has been completed
OccupancyGenerally taken to mean the number of occupied beds divided by the total number of beds, and expressed as a percentage. For example, hospital occupancy of 95% implies the beds have a patient in them 95% of the time