Prehospital and Disaster Medicine

Original Research

Resource Utilization in the Emergency Department of a Tertiary Care University-Based Hospital in Tokyo Before and After the 2011 Great East Japan Earthquake and Tsunami

Mai Shimadaa1, Aska Tanabea1, Masataka Gunshina1, Robert H. Riffenburgha2 and David A. Tanena3 c1

a1 Emergency Department, University of Tokyo, Tokyo, Japan

a2 Department of Clinical Investigations, Naval Medical Center, San Diego, California USA

a3 Emergency Department, Naval Medical Center, San Diego, California USA


Introduction The objective of this study was to determine the resource utilization of a tertiary care Japanese emergency department (ED) that was not immediately adjacent to the area of the 2011 Great East Japan earthquake and tsunami.

Methods A retrospective chart review was performed at a tertiary care university-based urban ED located approximately 290 km from the primary site of destruction secondary to an earthquake measuring 9.0 on the Richter Scale and the resulting tsunami. All patients who presented for a period of twelve days before and twelve days after the disaster were included. Data were collected using preformed data collection sheets, and stored in an Excel file. Abstracted data included gender, time in the ED, intravenous fluid administration, blood transfusion, oxygen, laboratories, electrocardiograms (ECGs), radiographs, ultrasound, diagnoses, surgical and medical referrals, and prescriptions written. Ten percent of the charts were reviewed for accuracy, and an error rate reported. Data were analyzed using 2-tailed t-tests, Fisher's exact tests or rank sum tests. Bonferroni correction was used to adjust P values for multiple comparisons.

Results Charts for 1193 patients were evaluated. The error rate for the abstracted data was 3.2% (95% CI, 2.4%-4.1%). Six hundred fifty-seven patients (53% male) were evaluated in the ED after the earthquake, representing a 23% increase in patient volume. Mean patient time spent in the ED decreased from 61 minutes to 52 minutes (median decrease from 35 minutes to 32 minutes; P = .005). Laboratory utilization decreased from 51% to 43% (P = .006). The percentage of patients receiving prescriptions increased from 48% to 54% (P = .002). There was no change in the number of patients evaluated for surgical complaints, but there was an increase in the number treated for medical or psychiatric complaints.

Conclusion There was a significant increase in the number of people utilizing the ED in Tokyo after the Great East Japan earthquake and tsunami. Time spent in the ED was decreased along with laboratory utilization, possibly reflecting decreased patient acuity. This information may help in the allocation of national resources when planning for disasters.

M Shimada, A Tanabe, M Gunshin, RH Riffenburgh, DA Tanen. Resource utilization in the emergency department of a tertiary care university-based hospital in Tokyo before and after the 2011 Great East Japan Earthquake and tsunami. Prehosp Disaster Med. 2012;27(6):1-4 .

(Received May 07 2012)

(Accepted July 21 2012)

(Revised August 26 2012)

(Online publication October 08 2012)


  • earthquake;
  • emergency department utilization;
  • emergency planning;
  • tsunami


c1 Correspondence: David A. Tanen, MD Naval Medical Center 34800 Bob Wilson Drive San Diego, CA 92134 USA E-mail