Adding More Beds to the Emergency Department or Reducing Admitted Patient Boarding Times: Which Has a More Significant Influence on Emergency Department Congestion?
Presented at the Society for Academic Emergency Medicine annual meeting, May 2007, Chicago, IL.
Received 2 November 2007; received in revised form 25 April 2008, 18 June 2008 and 24 June 2008; accepted 7 July 2008. published online 11 September 2008.
Study objective
We evaluate a computer simulation model designed to assess the effect on emergency department (ED) length of stay of varying the number of ED beds or altering the interval of admitted patient departure from the ED.
Methods
We created a computer simulation model (Med Model) based on institutional data and augmented by expert estimates and assumptions. We evaluated simulations of increasing the number of ED beds, increasing the admitted patient departure and increasing ED census, analyzing potential effects on overall ED length of stay. Multiple sensitivity analyses tested the robustness of the results to changes in model assumptions and institutional data.
Results
With a constant ED departure rate at the base case and increasing ED beds, there is an increase in mean length of stay from 240 to 247 minutes (95% confidence interval [CI] 0.8 to 12.6 minutes). When keeping the number of beds constant at the base case and increasing the rate at which admitted patients depart the ED to their inpatient bed, the mean overall ED length of stay decreases from 240 to 218 minutes (95% CI 16.8 to 26.2 minutes). With a 15% increase in daily census, the trends are similar to the base case results. The sensitivity analyses reveal that despite a wide range of inputs, there are no differences from the base case.
Conclusion
Our computer simulation modeled that improving the rate at which admitted patients depart the ED produced an improvement in overall ED length of stay, whereas increasing the number of ED beds did not.
aNorthwestern University, Department of Emergency Medicine, Feinberg School of Medicine, Chicago, IL
bInstitute for Healthcare Studies and Division of General Internal Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL
cDePaul University, Department of Management, Chicago, IL
Address for correspondence: Rahul K. Khare, MD, 259 E Erie St, Suite 100, Chicago, IL 60611
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article that might create any potential conflict of interest. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement. Research for this paper was done while Dr. Khare was a National Research Service Award (T32HS000078) postdoctoral fellow at the Institute for Healthcare Studies at Northwestern University under an institutional award from the Agency for Healthcare Research and Quality.
Author contributions: RKK conceived the study. ML collected the patient data. RKK, ESP, and GR built the model. GR analyzed the data. ESP drafted the article, and all authors contributed substantially to its revision. RKK takes responsibility for the paper as a whole.
Reprints not available from the authors.
Publication date: Available online September 9, 2008.
ABSTRACT