National Emergency Department Overcrowding Scale (Weiss SJ et al., Acad Emerg Med 2004) — a 0–200 operational index of emergency department crowding computed from 7 live variables. Type your numbers; the score updates instantly. Educational / operational use only — not medical advice, and not a guide for clinical decisions.
edPatients or admits.Where A = ED beds, B = hospital beds, C = total ED patients, D = ventilator patients, E = longest boarding wait (hours), F = boarding admits, G = waiting-room wait (hours). Raw scores below 0 are reported as 0; above 200 as 200.
Busy ED: 35 patients, 30 ED beds, 4 boarding admits, 400 hospital beds, 0 ventilated, 4-hour longest boarding wait, 1-hour waiting-room wait → NEDOCS = 95.46 — Extremely busy.
Disaster-level ED: 60 patients, 30 ED beds, 15 boarding admits, 400 hospital beds, 2 ventilated, 12-hour longest boarding wait, 3-hour waiting-room wait → raw 228.98, capped at 200 — Dangerously overcrowded (disaster).
NEDOCS stands for the National Emergency Department Overcrowding Scale, published by Weiss and colleagues in Academic Emergency Medicine (2004). It combines 7 live operational variables — ED census, ED beds, boarding admits, hospital beds, ventilator patients, longest boarding wait, and waiting-room wait — into a single 0 to 200 index. Higher scores mean a more crowded emergency department.
NEDOCS = 85.8 x (total ED patients / ED beds) + 600 x (boarding admits / hospital beds) + 13.4 x (ventilator patients) + 0.93 x (longest boarding wait in hours) + 5.64 x (waiting-room wait in hours) - 20. Raw scores below 0 are reported as 0 and scores above 200 are reported as 200.
Take an ED with 35 patients, 30 ED beds, 4 boarding admits, 400 hospital beds, 0 ventilated patients, a 4-hour longest boarding wait, and a 1-hour waiting-room wait. Term by term: 85.8 x (35/30) = 100.1; 600 x (4/400) = 6; 13.4 x 0 = 0; 0.93 x 4 = 3.72; 5.64 x 1 = 5.64. The sum is 115.46; minus 20 gives 95.46, which falls in the Extremely busy band (61-100).
A reported 200 means Dangerously overcrowded (disaster) — the top band, and the score is capped there. Example: 60 patients, 30 ED beds, 15 boarding admits, 400 hospital beds, 2 ventilated, 12-hour boarding wait, 3-hour waiting-room wait. Terms: 171.6 + 22.5 + 26.8 + 11.16 + 16.92 = 248.98; minus 20 = 228.98 raw, reported as 200.
0-20: Not busy. 21-60: Busy. 61-100: Extremely busy. 101-140: Overcrowded. 141-180: Severely overcrowded. 181-200: Dangerously overcrowded (disaster). The bands come from the original 2004 study.
Hours. Both the longest boarding wait (longest time a patient has waited for an inpatient bed) and the waiting-room wait (how long the last patient called from the waiting room waited) are entered in hours — for example, 90 minutes is 1.5 hours.
Boarding patients are patients who have been admitted to the hospital but are still physically waiting in the emergency department for an inpatient bed. They enter the formula twice: as a count (admits) in the 600 x (boarding admits / hospital beds) term, and through the longest boarding wait in hours.
With every input at zero the raw formula gives -20, which is reported as 0 — the Not busy band. The floor at 0 keeps the scale in its published 0 to 200 range.
Yes. Enter 0 for the waiting-room wait when the waiting room is empty, but the other six terms still count — an ED can be overcrowded from boarding alone (for example, 45 patients in 30 ED beds with no other load already scores 108.7, in the Overcrowded band).
No. It is an educational restatement of a published operations-research index for describing ED crowding levels. It is not medical advice, it does not guide clinical decisions or patient care, and it cannot replace the judgment of qualified health care professionals and hospital leadership.
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