Validation of EDWIN and Modified EDWIN in Emergency Room of Rajavithi Hospital.
Piyawadee Chaichanpimol, MD; Pairoj Khruekarnchana, MD; Nalinas Khunkhlai, MD
Emergency Department, Rajavithi Hospital
Objectives : To validate EDWIN and modified EDWIN score for measuring the size of crowd
in quantitative term in emergency room of Rajavithi Hospital.
Methods : Prospective observational analytical study was done during September 1 -30 ,2008
by collecting the data of patients under 3-grouped triage system in emergency room of Rajavithi
hospital at 6 points of time which were 1am, 5am, 9am, 1pm, 5pm and 9pm. The opinions
about level of workload in ED at each point of times of emergency physicians and nurses on
duty were compared and measured by the Single-question Likert-type instrument. On the
analytical process, we used the weighted kappa statistics in the test of the agreement of
measurement between emergency physicians and nurses, the Kruskal-Wallis chi-square test in
measuring the association between EDWIN and modified EDWIN and the Pearson and
Spearman’s rho in comparing the correlation of both scores. The AROC (Area under the
Receiver Operating characteristic Curve) was used to compare the efficiency of detecting the
ED overcrowding between EDWIN and modified EDWIN. The statistical computer software
was SPSS v.17.0.
Results : The overall data was collected in 178 points of time with 2 missings. The mean of
EDWIN was 0.21 (SD 0.09) and modified EDWIN was 0.04 (SD 0.018). The Pearson
Correlation and Spearman’s rho proved the association of both scores (p < 0.001). There was a
fair agreement about the degree of crowding in ED between emergency physicians and nurses
(weighted K 0.556, p<0.001). The descriptive statistics of EDWIN were categorized into three
levels by the doctor’s opinion: “not busy or crowded” (score 1-2) giving the mean 0.17 ,and
median 0.15 (IQR = 0.11-0.22), “average”(score 3) giving the mean 0.21, and median 0.2 (IQR
= 0.16-0.27) and “busy, crowded”(score 4-5) giving the mean 0.26 and median 0.25 (IQR =
0.19-0.32). In the modified EDWIN, the mean of the “not busy or crowded” group was 0.04
and the median was 0.03 (IQR = 0.02-0.04), for the “average” group, the mean was 0.05 and
the median was 0.04 (IQR = 0.04-0.06).In the last group, “busy, crowded”, the mean was 0.06
and the median was 0.05 (IQR = 0.04-0.07). The modified EDWIN can slightly improve the
prediction of the ED overcrowding compared with the EDWIN. (AROC modified EDWIN =
0.76 (95%CI 0.68-0.84); AROC EDWIN = 0.71 (95%CI 0.63-0.8), p<0.001). The maximum
score of EDWIN and modified EDWIN are at 1 am and 5 pm in order.
Conclusions : The EDWIN and modified EDWIN could be used as tools to measure the
quantitative data of the size of crowd in emergency room of Rajavithi hospital. The “not busy
or crowded” group has the EDWIN <0.15, the modified EDWIN <0.03, the “average” group has
the EDWIN 0.15-0.2, the modified EDWIN 0.03-0.06 and the “busy, crowded” group has the
EDWIN > 0.2, the modified EDWIN > 0.06.
Keywords : ED Overcrowding, ED Crowding, Emergency Department Work Index, Scores,