International Crowding Measure in Emergency Departments (ICMED)
| Measure | Operational definition |
|---|---|
| Input measures | |
| 1. Ability of ambulances to offload patients | An ED is crowded when the 90th centile time between ambulance arrival and offload is greater than 15 min |
| 2. Patients who leave without being seen or treated (LWBS) | An ED is crowded when the number of patients who LWBS is greater than or equal to 5% |
| 3. Time until triage | An ED is crowded when there is a delay greater than 5 min from patient arrival to begin their initial triage |
| Throughput measures | |
| 4. ED occupancy rate | An ED is crowded when the occupancy rate is greater than 100% |
| 5. Patients’ total length of stay in the ED* | An ED is crowded when the 90th centile patient's total length of stay is greater than 4 h. |
| 6. Time until a physician first sees the patient | An ED is crowded when an emergent (one ortwo) patient waits longer than 30 min to be seen by a physician |
| Output measures | |
| 7. ED boarding time† | An ED is crowded when less than 90% of patients have left the ED 2 h after the admission decision |
| 8. Number of patients boarding in the ED‡ | Boarders are defined as admitted patients waiting to be placed in an inpatient bed. An ED is crowded when there is greater than 10% occupancy of boarders in the ED |
*For example, in an ED with 50 patients inside, if more than five patients had been there longer than 4 h, then this would count as a violation.
†For example, in an ED with 10 patients who are waiting for admission, if more than one of these patients had waited longer than 2 h, then this would count as a violation.
‡For example, in an ED with 50 patients inside, if more than five patients are waiting for admission, then this would count as a violation.
ED, emergency department.