Background: Emergency Department (ED) overcrowding has been described as a major public health problem regarding its impact on the outcome of healthcare process.
Objective(s): To measure the level of ED crowding using the National Emergency Department Overcrowding Scale (NEDOCS) and ED occupancy.
Methods: An Analytical cross-sectional study was conducted in the ED of a 144 bed general hospital in Alexandria, Egypt among 168 sampling instances of ED visits. NEDOCS score (developed by Weiss et al.) was calculated using a web-based calculator and the occupancy rate was calculated as the total number of ED patients divided by the number of licensed ED beds.
Results: The mean NEDOCS score ranged from 19 to 200 indicating an overcrowded status in 59.3% of occasions. The ED occupancy ranged from 18.18 % to 272.73 % and exceeded 100 % in 66 % of measurements.  The average NEDOCS score, ED occupancy and number of Left without being Seen (LWBS) differed significantly per hour  being highest from 10 A.M. till 14 P.M. (p= 0.000) while only the average NEDOCS score number and LWBS patients differed by weekday (p=0.004 and 0.005 respectively). The daily number of LWBS patients showed a moderate positive correlation with NEDOCS score (Spearman's rho = 0.648, p= .0000) and the ED occupancy (Spearman's rho = 0.650, p < .001)
Conclusion: There is a high level of ED overcrowding and ED occupancy which is affected by time of the day and the weekday. Overcrowding is associated with more LWBS patients.