Administration of Emergency Medicine| Volume 43, ISSUE 4, P736-744, October 2012

An Association Between Occupancy Rates in the Emergency Department and Rates of Violence Toward Staff

Published:February 13, 2012DOI:



      Studies have explored possible causes of violent acts in the emergency department (ED), however, the association of violence with ED crowding has not been studied. Although the total number of violent acts would be expected to increase, it is not clear if the rate of violent acts also increases as occupancy levels rise.


      The purpose of this study was to determine if there is an association between occupancy rates in the ED and rates of violence toward staff.


      This was a retrospective chart review study. Violent incidents in a community, Level I trauma center ED were identified from review of orders of emergency detainment, adverse event forms, physical restraint logs, and pharmacy records from January 1, 2005 to June 1, 2008. Occupancy rates for all days were calculated and violent vs. non-violent days were compared using a standard two-sample t-test. Logistic regression analysis was then used to investigate other factors associated with violent incidents.


      A rate of violence of 1.3 incidents per 1000 patients was found. When comparing the occupancy rates of violent days (mean 95%, SD 26%) with non-violent days (mean 86%, SD 24%), a statistically significant association was found (p<0.0001). Multivariate logistic regression confirmed a significant association between crowding and violence toward staff (odds ratio 4.290, 95% confidence interval 2.137–8.612).


      These results suggest another possible negative effect that crowding has on ED staff and physicians. Policies and recommendations regarding ED operating procedures and staff safety during times of higher occupancy levels should be discussed.


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