Connect
MJA
MJA

Increase in patient mortality at 10 days associated with emergency department overcrowding

Drew B Richardson
Med J Aust 2006; 184 (5): 213-216.

Summary

Objective: To quantify any relationship between emergency department (ED) overcrowding and 10-day patient mortality.

Design and setting: Retrospective stratified cohort analysis of three 48-week periods in a tertiary mixed ED in 2002–2004. Mean “occupancy” (a measure of overcrowding based on number of patients receiving treatment) was calculated for 8-hour shifts and for 12-week periods. The shifts of each type in the highest quartile of occupancy were classified as overcrowded.

Participants: All presentations of patients (except those arriving by interstate ambulance) during “overcrowded” (OC) shifts and during an equivalent number of “not overcrowded” (NOC) shifts (same shift, weekday and period).

Main outcome measure: In-hospital death of a patient recorded within 10 days of the most recent ED presentation.

Results: There were 34 377 OC and 32 231 NOC presentations (736 shifts each); the presenting patients were well matched for age and sex. Mean occupancy was 21.6 on OC shifts and 16.4 on NOC shifts. There were 144 deaths in the OC cohort and 101 in the NOC cohort (0.42% and 0.31%, respectively; P = 0.025). The relative risk of death at 10 days was 1.34 (95% CI, 1.04–1.72). Subgroup analysis showed that, in the OC cohort, there were more presentations in more urgent triage categories, decreased treatment performance by standard measures, and a higher mortality rate by triage category.

Conclusions: In this hospital, presentation during high ED occupancy was associated with increased in-hospital mortality at 10 days, after controlling for seasonal, shift, and day of the week effects. The magnitude of the effect is about 13 deaths per year. Further studies are warranted.

  • Drew B Richardson

  • Emergency Department, Canberra Hospital, Australian National University Medical School, Canberra, ACT.

Correspondence: 

Acknowledgements: 

I would like to thank Dr Bruce Shadbolt for statistical input and advice.

Competing interests:

None identified.

  • 1. Dunn R. Reduced access block causes shorter emergency department waiting times: an historical control observational study. Emerg Med (Fremantle) 2003; 15: 232-238.
  • 2. Schull MJ, Morrison LJ, Vermeulen M, Redelmeier DA. Emergency department overcrowding and ambulance transport delays for patients with chest pain. CMAJ 2003; 168: 277-283.
  • 3. Fernandes CM. Emergency department overcrowding: what is our response to the “new normal”? Acad Emerg Med 2003; 10: 1096-1097.
  • 4. Richardson DB. The access block effect: relationship between delay to reaching an inpatient bed and inpatient length of stay. Med J Aust 2002; 177: 492-495. <MJA full text>
  • 5. Liew D, Liew D, Kennedy MP. Emergency department length of stay independently predicts excess inpatient length of stay. Med J Aust 2003; 179: 524-526. <MJA full text>
  • 6. Richardson DB. Validation of the refined overcrowding scale: a case-control study. [Abstract] Acad Emerg Med 2004; 12: 5.
  • 7. Hwang U, Concato J. Care in the emergency department: how crowded is overcrowded? Acad Emerg Med 2004; 11: 1097-1101.
  • 8. Richardson DB. Prospective validation of point occupancy definition of overcrowding. [Abstract] Acad Emerg Med 2004; 11: 462.
  • 9. Australasian College for Emergency Medicine. The Australasian Triage Scale. Emerg Med (Fremantle) 2002; 14: 335-336.
  • 10. Australian Council on Healthcare Standards. Clinical indicators — emergency medicine. Version 2. Sydney: ACHS; 2002.
  • 11. Australasian College for Emergency Medicine. Standard terminology. Emerg Med (Fremantle) 2002; 14: 337-340.
  • 12. Trzeciak S, Rivers EP. Emergency department overcrowding in the United States: an emerging threat to patient safety and public health. Emerg Med J 2003; 20: 402-405.
  • 13. Fatovich DM, Nagree Y, Sprivulis P. Access block causes emergency department overcrowding and ambulance diversion in Perth, Western Australia. Emerg Med J 2005; 22: 351-354.
  • 14. Forster AJ, Stiell I, Wells G, et al. The effect of hospital occupancy on emergency department length of stay and patient disposition. Acad Emerg Med 2003; 10: 127-133.

Author

remove_circle_outline Delete Author
add_circle_outline Add Author

Comment
Do you have any competing interests to declare? *

I/we agree to assign copyright to the Medical Journal of Australia and agree to the Conditions of publication *
I/we agree to the Terms of use of the Medical Journal of Australia *
Email me when people comment on this article

Responses are now closed for this article.