national emergency department overcrowding study tool is not useful in an australian emergency...
TRANSCRIPT
Emergency Medicine Australasia
(2006)
18
282ndash288 doi 101111j1742-6723200600854x
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
Blackwell Publishing AsiaMelbourne AustraliaEMMEmergency Medicine Australasia1742-67312006 Blackwell Publishing Asia Pty Ltd2006183282288Miscellaneous
Web based ED overcrowding assessmentK Raj
et al
Correspondence Dr Kamini Raj 24 Gila Place Ipswich Qld 4300 Australia Email kamini_rajhealthqldgovau
Kamini Raj MB BS Emergency Registrar Kylie Baker MB BS FACEM Emergency Physician Stephan Brierley MB BS FRACGP FRACMADirector of Emergency Department Duncan Murray MB BS FACEM Emergency Physician
M
ANAGEMENT
amp Q
UALITY
National Emergency Department Overcrowding Study tool is not useful in an Australian emergency department
Kamini Raj Kylie Baker Stephan Brierley and Duncan Murray
Department of Emergency Medicine Ipswich General Hospital Ipswich Queensland Australia
Abstract
Objective
To determine the accuracy and usefulness of the National Emergency Department Over-crowding Study (NEDOCS) tool in an urban hospital ED in Australia by direct comparisonwith subjective assessment by senior ED staff
Method
A sample of simultaneous subjective and objective data pairs were collected six times aday for a period of 3 weeks All senior medical staff in the ED answered a brief question-naire along with the senior charge nurse for the ED Simultaneously the senior chargenurse also documented the total number of patients in the ED the number of patientsawaiting admission the number of patients on ventilators the longest time waited by anED patient for ward bed and the waiting time for the last patient from the Waiting Roomplaced on a trolley The objective indicators were entered into a Web-based NEDOCS tooland transformed scores were compared with the averaged and transformed subjectivescores for each sample time BlandndashAltmann and Kappa statistics were used to test theagreement between the objective and subjective measuring methods
Results
The mean difference between the subjective and objective methods was small (35 [95confidence interval
minus
0875ndash7878] ) however the 95 limits of agreement was wide(
minus
4652ndash5343) The Kappa statistic used to assess the extent of reproducibility betweencategorical variables was 031 (95 confidence interval 017ndash045)
Conclusion
The present study suggests that NEDOCS method of processing the objective overcrowd-ing data does not accurately reflect the subjective assessment of the senior staff workingat that time in the ED This might be because the assumptions of the original NEDOCSstudy are flawed
Key words
Australian emergency department
emergency department
National Emergency DepartmentOvercrowding Study tool
objective score
overcrowding
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
283
Introduction
ED overcrowding is a growing issue worldwide Overthe years various articles in the press
12
governmentreports and journals
34
have highlighted this issue Itwas first documented in Australia in a Sydney metro-politan hospital in late 1980
5
Overcrowding of the EDhas been demonstrated to have negative effect onpatient care
6ndash8
staff satisfaction and health
910
Early warning of overcrowding would allow an orga-nizational response to prevent any potential adverseoutcomes Strategies could include calling in of extrastaff
1112
changing management strategies
13ndash17
hospitalambulance bypass and notification of neighbouringhospitals There is need for a tool which can rapidlyand accurately forewarn of overcrowding
18
Arguably the most accurate indicators of overcrowd-ing are the adverse events and complaints
19
but thereis a delay in notification and correlation They are nothelpful as an early warning system
The computerization of hospital admissions opensthe possibility of a computer generated automatic andobjective warning system
20
Weiss and colleagues have explored the relationshipof the computer-generated indicators of overcrowdingwith the subjective assessment by senior staff atthe time of sampling This model is called NationalEmergency Department Overcrowding Study(NEDOCS) tool
21
The NEDOCS tool was produced to lsquoquantitativelydescribe the staffrsquos sense of overcrowdingrsquo in varioussized academic ED in the USA It was recognized thatthere is currently no gold standard measure of ED overcrowding so a qualitative measure of overcrowdingwas devised and described by same team
22
This qual-itative measure was transformed into the subjectivescore The NEDOCS Tool is a Web-based calculatorwhich converts a simple dataset into a number (objec-tive score) said to correlate accurately with degree ofovercrowding as perceived by senior staff working atthe time (subjective score) The NEDOCS tool has beendeveloped for the use in clinical setting It began as a23 site-sampling questionnaire reflecting the subjectiveassessment of ED physicians
22
which was then statis-tically reduced using mixed effect linear regression todevelop a 5-questionnaire model The validity of thereduced model was tested using a bootstrap techniqueand was found to reflect the full model with 88 accu-racy The NEDOCS tool was also found to correlate wellwith the number of patients who left without beingseen
23
in further trials by the inception team
There has been an interest in implementing theNEDOCS tool in Australia
The objective of the present study was to assess theusefulness and accuracy of the Web-based model of theNEDOCS tool in an Australian ED compared with sub-jective clinician assessment
Method
Ipswich Hospital is a 317-bed non-tertiary urban hos-pital located in Ipswich Qld Australia with an annualED attendance of over 42 000 The ethics committee forIspwich Hospital approved the study Patient consentwas not required
The present prospective pilot study covered a sampleperiod of 3 weeks from 20 December 2004 to 10 January2005 Samples were collected at four hourly intervals(100 500 900 1300 1700 and 2100 hours) Themethod duplicated the original paper by Weiss
21
exceptthat sample times were not randomized and the studywas undertaken in a single hospital The samples werecollected six times a day although the study by Weisscovered each sample time twice only in the 3 weekperiod
The composite outcome variable score (subjectivescore) was calculated as follows On each shift betweenone and four senior medical officers present completeda short survey consisting of two Likert type scales(Appendices 12) rating the lsquoDegree of overcrowdingrsquoand lsquoFeeling of being rushedrsquo No instructions or defini-tions other than the terms presented were given Thesenior charge nurse of the ED was asked independentlybut simultaneously to rate the degree of overcrowdingusing the same scale The senior charge nurse was notasked to rate lsquoFeeling of being rushedrsquo The even Likertscale was used so that a break point for lsquonot over-crowdedrsquo versus lsquoovercrowdedrsquo fell between 3 and 4Each timed and dated survey form was placed in asealed box in ED In keeping with the Weiss
21
study forease of interpretation the six-point scale was convertedto a scale ranging from 0 to 200 (0
=
not busy40
=
busy 80
=
extremely busy but not overcrowded120
=
overcrowded 160
=
severely overcrowded 200
=
dangerously overcrowded)The survey results of lsquoDegree of overcrowdingrsquo and
lsquoFeeling of being rushedrsquo were averaged for all seniorphysicians and charge nurse for the ED working at thetime of data collection These averaged results formedthe lsquooutcome variablersquo or lsquocomposite scorersquo This scorecomprised the subjective rating of each paired sample
K Raj
et al
284
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
Interrater agreement was tested retrospectively onthe composite outcome data collected in the first weekThe intraclass correlation coefficient was calculated forthe responses to the lsquofeeling rushedrsquo question askedfrom the doctors and then again for the lsquoovercrowdingrsquoquestion asked from the doctors and the charge nurse
The objective rating in each sample pair was calcu-lated by the Web-based NEDOCS Calculating Tool
24
using the following objective measurements1 Total number of patients in ED occupying beds
(Patients in waiting area were not included)2 Total number of patients on ventilators3 Total number of patients awaiting admission4 Waiting time for the last patient called in from wait-
ing room (Patient occupying ED bed waiting to beseen by the physician)
5 Longest time patient waiting for admission6 Number of beds in ED7 Number of total beds (occupied and vacant) in
hospitalThe first five variable objective measures were collectedsimultaneously and prospectively using a prepareddata sheet subsequently placed in a sealed box in EDThe ED attendance screen was printed at the same timeto check for the accuracy of data collection
The NEDOCS Calculating Tool amalgamated theseven objective data points for each time of data collec-tion and rated the data for that sample time on follow-ing scale 0ndash20
=
not busy 20ndash60
=
busy 60ndash100extremely busy but not overcrowded 100ndash140
=
overcrowded 140ndash180 severely overcrowded180ndash200
=
dangerously overcrowdedBeing a pilot study we aimed to duplicate Weissrsquos
sample method for the same time duration as in originalstudy
21
rather than calculate a new sample size How-ever we used different statistical analysis as we hadconcerns about the product moment correlation (
r
) coef-ficient used by Weiss The valid use of correlation coef-ficient requires a null hypothesis stating that there isno relationship between the two statistics This wouldnot be the case as both subjective and objective scoresare being collected at the same time to assess the samething that is lsquoovercrowdingrsquo In our pilot study theBlandndashAltman
2526
plot was chosen for statistical analy-sis to compensate for this error Differences betweenmeasurements within each pair were plotted on the
Y
-axis The averages of the two measurements were plot-ted on the
X
-axis The average was used as this wasthe closest estimate of the true result in the absence ofa gold standard for lsquoover-crowdingrsquo The mean differ-ence of all pairs was also calculated reflecting the
lsquoestimated biasrsquo or the systematic difference betweenthe two methods
Kappa statistics were used to analyse agreementbetween subjective and objective measures as well asassessment of interrater agreement on subjectiveresponses
Results
During the 3 week study period 2293 patients attendedthe ED an average of 109 patients per day For theentire 2004 calendar year the Ipswich Hospital ED aver-aged 115 patients per day
One hundred and twenty-eight sample times weredescribed by two scores (subjective and NEDOCS)over 3 weeks The datasets for the 3 week period werecomplete
Figure 1 shows a scatter diagram of transformedsubjective and objective (NEDOCS) scores Figure 2shows that the mean difference between the methods ofmeasurement is small (347 95 confidence interval[CI]
minus
0875ndash7878) Figure 2 also illustrates that therange of the 95 limits of agreement are wide (
minus
4652ndash5343)
The BlandndashAltman plot shows that in 5 of themeasurements one method of measurement is likely tobe more than 100-point raw score or 25 categoriesbeyond the other In the present study 16 pairs (125[95 CI 78ndash193]) had scores more than 40 points (onewhole category) apart and 49 pairs (38 [95 CI 30ndash469]) had scores in adjacent categories The kappavalue of 031 (95 CI 017ndash045) suggests poor agree-ment between the categorical scores
Interrater agreement of the subjective responses usedin the composite outcome score was high The intraclasscorrelation coefficient was 087 (95 CI 071ndash095) forthe question on lsquofeeling rushedrsquo For the lsquodegree of over-crowdingrsquo the intraclass correlation coefficient was 094(95 CI 082ndash097)
Discussion
The present study demonstrates that the NEDOCS toolcorrelated poorly with subjective clinician assessmentof overcrowding in our ED The poor correlation is veryobvious looking at Figure 2 The 95 limits of agree-ment are wide (more than two categories apart) makingthe NEDOCS tool imprecise when used in clinical set-ting Such imprecision is unacceptable if one is
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
285
considering up scaling hospital responses based purelyon the NEDOCS score In addition Figure 1 shows usthat there is no specific relationship between the NEDOCSand subjective scores These findings indicate that theNEDOCS tool is not ready to be used in Australia
Our findings might differ from Weissrsquos original studyfor several reasons The NEDOCS tool was developed
in the USA and might not be applicable in a regionalAustralian hospital with different patient flow andstaffing profile
The difference in findings may be partly explainedby our decision to use different statistical methodologyto Weiss and to interpretation of data results Weissused product moment correlation (
r
) coefficient for
Figure 1
Scatter diagram comparison of both raw scores (
) National Emergency Department Overcrowding Study (NEDOCS) andcomposite score
150
125
100
75
50
Com
posi
te_O
utco
me_
Var
iabl
e_S
core
25
00 25 50
NEDOCS_Score
75 100
Figure 2
BlandndashAltman plot
50
75
25
0
minus25
Diff
eren
ce b
etw
een
met
hods
minus75
minus50
0 25 50Average of both scores
75 100 125
95 confidence interval formean difference= minus0875 to 7828
95 limits of agreement= 5343 to minus4652
upper limit of agreement
mean diff =3476
lower limit of agreement
standard deviation = 2498
K Raj
et al
286
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
statistical analysis in their original study and the basisof its calculation may be questioned They concludedthat the NEDOCS score accurately reflects staffrsquos senseof lsquoovercrowdingrsquo quoting R
2
049 for the full model TheNEDOCS tool reflects the full model with 88 accuracyso it is even less accurate
Weiss quoted a high interrater agreement (correlationcoefficient 086ndash093) between physiciansrsquo and nursesrsquoLikert results and between each result and the averageas a justification for their use as composite outcomescore The Likert like scale used for subjective scoreswere developed from a preliminary survey of EDdirectors
22
who identified lack of ED beds ED closureand ambulance diversion patients managed in hall-ways full waiting rooms feeling lsquorushedrsquo and a wait ofgreater than 1 h to see a physician as evidence of EDovercrowding
The statistical analysis of the data where one mea-surement method (subjective score) is compared withanother measurement method (objective score) can befraught with danger When there is no gold standard tocompare the new measuring tool the statistical analysismust take into consideration the possible error of eachmethod For that reason we chose the BlandndashAltmanplot and subsequently demonstrated poor agreement
A review of the literature highlights the difficulty indefining overcrowding Hwang
et al
27
reviewed the lit-erature over 26 years and found a total of 230 articlesrelating to overcrowding in the ED including originalarticles reviews and editorials Only 23 of these hadexplicit definitions of overcrowding There was sub-stantial variation in the definition of lsquoovercrowding inthe EDrsquo within these articles The definitions focused onspecific issues like waiting time hospital-related butnon-ED factors or factors external to the hospital suchas ambulance diversions to describe overcrowding
There is little literature documenting quantitativemeasurements of overcrowding in the ED
2021
Bernstein
et al
developed the lsquoEmergency Department WorkIndexrsquo (EDWIN index) which included (i) number ofpatients in triage category (ii) triage category (iii)number of attending physicians on duty (iv) numberof treatment bays and (v) number of admitted patientsin ED The limitation of EDWIN index is that it is nota computer-based model It does not take into accountvarious other issues such as the role of a resident inED and also does not have any input from nursingstaff
Weiss
et al
2122
recognized this deficit in knowledgeand undertook the difficult but important task of devel-oping a computer-based objective model In its current
form this computer-based model NEDOCS tool has cor-related poorly with staffrsquos sense of overcrowding in ourhospital For the moment subjective assessment seemsto be the best method of assessing overcrowding untilwe find a better tool or refine the NEDOCS scoringmethod
The NEDOCS scoring method is easy simple andquick to use and could become a more important anduseful tool with further refinement A refined NEDOCStool may provide us with the definitions and scoringtool we need As Weiss suggests measurements thatinclude case mix within ED triage category and skillmix of staff may improve agreement between NEDOCSscore and staffrsquos perception of lsquoovercrowdingrsquo
There are several limitations to the present study Atno time during the study was the department severelyor dangerously overcrowded Correlation might bebetter or worse at these extreme times The study wasconducted at only one urban hospital ED with mixedchildren and adult presentations and might not be appli-cable to other systems or private ED The biggest lim-itation of the present study however is the lack of alsquogold standardrsquo by which to define ED overcrowdingWe chose to use subjective physiciannurse assessmentas the gold standard by which to measure the NEDOCStool It is possible that the NEDOCS tool might actuallybe very good and that staff subjective assessment isactually poor
Conclusion
The NEDOCS tool was not valid in our setting and hasbeen inconsistent in reflecting staffrsquos sense of lsquoover-crowdingrsquo for which it was primarily designedNEDOCS is still a potentially important tool worthy ofrefinement
Acknowledgements
I would like to acknowledge the assistance of all staffof the ED Ipswich General Hospital for helping to col-lect the data
Author contributions
KR conceived and designed the study collected the dataand wrote the manuscript KB assisted with some sta-tistics and manuscript editing SB and DM edited andassisted in writing the manuscript
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
287
Competing interests
None declared
Accepted 13 February 2006
References
1 Eisenberg D Woodbury R Willwerth J Brice LE Sieger MDonely M Critical condition
Time
2000
155
0040781X
2 Gibbs N Browning S Do you want to die
Time
1990
135
0040781X 90
3 Adrulis DP Kellrmann A Hintz E Hackman BB Weslowski VBEmergency departments and crowding in United States teachinghospitals
Ann Emerg Med
1991
20
980ndash60
4 Committee on Pediatric Emergency Medicine American acad-emy of pediatrics overcrowding crisis in our nationrsquos emergencydepartment is our safety net unraveling
Pediatrics
2004
114
878ndash88
5 Access block and overcrowding in emergency department Posi-tion paper Australian College for Emergency Medicine down-loaded on 2005 Available from URL httpwwwacemorgauopendocumentsaccessbookbackpdf [Accessed December2004]
6 Derlet RM Richards JR Overcrowding in the nations emergencydepartment complex causes and disturbing effects
Ann EmergMed
2000
35
63ndash8
7 Miro O Antonio MT Jimenez S
et al
Decreased health carequality associated with emergency department overcrowding
Eur J Emerg Med
1999
6
105ndash7
8 Fatovich DM Nagree Y Sprivulis P Access block causes emer-gency department overcrowding and ambulance diversion inPerth Western Australia
Emerg Med J
2005
22
351ndash4
9 Henson VL Vickey DL Patient self discharge from the emer-gency department who is at risk
Emerg Med J
2005
22
499ndash501
10 Fernandes CM Daya MR Barry S Palmer N Emergency depart-ment patients who leave without seeing a physician the TorontoHospital experience
Ann Emerg Med
1994
24
1092ndash6
11 Shaw KN Lavelle JM VESAS a solution to seasonal fluctuationsin emergency department census
Ann Emerg Med
1998
32
698ndash702
12 Saint Lamont S lsquoSee and Treatrsquo spreading like wildfire A qual-itative study into factors affecting its introduction and spread
Emerg Med J
2005
22
548ndash52
13 Anonymous To ease overcrowding delay elective surgeries
EdManag
2005
17
29ndash31
14 Anonymous Three strategies to reduce overcrowding
EdManag
2004
16
1ndash16
15 Anonymous Itrsquos not business as usual you can fight patientsurges with an aggressive plan
Ed Manag
2003
15
121ndash4
16 Kelen GD Scheulen JJ Hill PM Effect of an emergency depart-ment (ED) managed acute care unit on ED overcrowding andemergency medical services diversion
Acad Emerg Med
2001
8
1095ndash100
17 Lynn SG Kellermann A Critical decision making managing theemergency department in an overcrowded hospital
Ann EmergMed
1991
20
287ndash92
18 Reeder TJ Garrison HG When the safety net is unsafe real-timeassessment of the overcrowded emergency department
AcadEmerg Med
2001
8
1070ndash4
19 Wolff AM Bourke J Detecting and reducing adverse events inan Australian rural base hospital emergency department usingmedical screening and review
Emerg Med J
2002
19
35ndash40
20 Bernstein SL Verghese V Leung W Lunney AT Perez I Devel-opment and validation of a new index to measure emergencydepartment crowding
Acad Emerg Med
2003
10
938ndash42
21 Weiss SJ Derlet R Arnold J
et al
Estimating the degree ofemergency department overcrowding in academic medical cen-ters result of the National ED Overcrowding Study (NEDOCS)
Acad Emerg Med
2004
11
38ndash50
22 Weiss SJ Amdhal J Ernst AA Derlet R Richards J Nick TGDevelopment of site sampling form for evaluation of ED over-crowding
Med Sci Monit
2002
8
CR549ndash53
23 Weiss SJ Ernst AA Derlet R King R Bair A Nick TG Rela-tionship between the National ED Overcrowding Scale and thenumber of patients who leave without being seen in an academicED
Am J Emerg Med
2005
23
288ndash94
24 NECDOCS Calculating Tool Available from URL httphscunmeduemermednedocs_finshtml
25 Martin Bland J Altman DG Comparing methods of measure-ment why plotting difference against standard method is mis-leading
Lancet
1995
346
1085ndash7
26 Martin Bland J Altman DG Statistical method for assessingbetween two methods of clinical measurements
Lancet
1986
i
306ndash10
27 Hwang U Concato J Care in the emergency department howcrowded is overcrowded
Acad Emerg Med
2004
11
1097ndash101
Appendix I
Survey form for ED physician for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the opinion on lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy but not overcrowded4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
Please circle the opinion on lsquoFeeling rushedrsquo in ED1 2 3 4 5 61 = not rushed6 = rushed
K Raj et al
288 copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
After completing the survey form please place it intosealed box provided in Emergency DepartmentED emergency department NEDOCS National Emer-gency Department Over Crowding Study
Appendix II
Survey form for the charge nurse in ED for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
After completing the survey form please place it in thesealed box provided in Emergency DepartmentED emergency department NEDOCS NationalEmergency Department Over Crowding Study
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
283
Introduction
ED overcrowding is a growing issue worldwide Overthe years various articles in the press
12
governmentreports and journals
34
have highlighted this issue Itwas first documented in Australia in a Sydney metro-politan hospital in late 1980
5
Overcrowding of the EDhas been demonstrated to have negative effect onpatient care
6ndash8
staff satisfaction and health
910
Early warning of overcrowding would allow an orga-nizational response to prevent any potential adverseoutcomes Strategies could include calling in of extrastaff
1112
changing management strategies
13ndash17
hospitalambulance bypass and notification of neighbouringhospitals There is need for a tool which can rapidlyand accurately forewarn of overcrowding
18
Arguably the most accurate indicators of overcrowd-ing are the adverse events and complaints
19
but thereis a delay in notification and correlation They are nothelpful as an early warning system
The computerization of hospital admissions opensthe possibility of a computer generated automatic andobjective warning system
20
Weiss and colleagues have explored the relationshipof the computer-generated indicators of overcrowdingwith the subjective assessment by senior staff atthe time of sampling This model is called NationalEmergency Department Overcrowding Study(NEDOCS) tool
21
The NEDOCS tool was produced to lsquoquantitativelydescribe the staffrsquos sense of overcrowdingrsquo in varioussized academic ED in the USA It was recognized thatthere is currently no gold standard measure of ED overcrowding so a qualitative measure of overcrowdingwas devised and described by same team
22
This qual-itative measure was transformed into the subjectivescore The NEDOCS Tool is a Web-based calculatorwhich converts a simple dataset into a number (objec-tive score) said to correlate accurately with degree ofovercrowding as perceived by senior staff working atthe time (subjective score) The NEDOCS tool has beendeveloped for the use in clinical setting It began as a23 site-sampling questionnaire reflecting the subjectiveassessment of ED physicians
22
which was then statis-tically reduced using mixed effect linear regression todevelop a 5-questionnaire model The validity of thereduced model was tested using a bootstrap techniqueand was found to reflect the full model with 88 accu-racy The NEDOCS tool was also found to correlate wellwith the number of patients who left without beingseen
23
in further trials by the inception team
There has been an interest in implementing theNEDOCS tool in Australia
The objective of the present study was to assess theusefulness and accuracy of the Web-based model of theNEDOCS tool in an Australian ED compared with sub-jective clinician assessment
Method
Ipswich Hospital is a 317-bed non-tertiary urban hos-pital located in Ipswich Qld Australia with an annualED attendance of over 42 000 The ethics committee forIspwich Hospital approved the study Patient consentwas not required
The present prospective pilot study covered a sampleperiod of 3 weeks from 20 December 2004 to 10 January2005 Samples were collected at four hourly intervals(100 500 900 1300 1700 and 2100 hours) Themethod duplicated the original paper by Weiss
21
exceptthat sample times were not randomized and the studywas undertaken in a single hospital The samples werecollected six times a day although the study by Weisscovered each sample time twice only in the 3 weekperiod
The composite outcome variable score (subjectivescore) was calculated as follows On each shift betweenone and four senior medical officers present completeda short survey consisting of two Likert type scales(Appendices 12) rating the lsquoDegree of overcrowdingrsquoand lsquoFeeling of being rushedrsquo No instructions or defini-tions other than the terms presented were given Thesenior charge nurse of the ED was asked independentlybut simultaneously to rate the degree of overcrowdingusing the same scale The senior charge nurse was notasked to rate lsquoFeeling of being rushedrsquo The even Likertscale was used so that a break point for lsquonot over-crowdedrsquo versus lsquoovercrowdedrsquo fell between 3 and 4Each timed and dated survey form was placed in asealed box in ED In keeping with the Weiss
21
study forease of interpretation the six-point scale was convertedto a scale ranging from 0 to 200 (0
=
not busy40
=
busy 80
=
extremely busy but not overcrowded120
=
overcrowded 160
=
severely overcrowded 200
=
dangerously overcrowded)The survey results of lsquoDegree of overcrowdingrsquo and
lsquoFeeling of being rushedrsquo were averaged for all seniorphysicians and charge nurse for the ED working at thetime of data collection These averaged results formedthe lsquooutcome variablersquo or lsquocomposite scorersquo This scorecomprised the subjective rating of each paired sample
K Raj
et al
284
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
Interrater agreement was tested retrospectively onthe composite outcome data collected in the first weekThe intraclass correlation coefficient was calculated forthe responses to the lsquofeeling rushedrsquo question askedfrom the doctors and then again for the lsquoovercrowdingrsquoquestion asked from the doctors and the charge nurse
The objective rating in each sample pair was calcu-lated by the Web-based NEDOCS Calculating Tool
24
using the following objective measurements1 Total number of patients in ED occupying beds
(Patients in waiting area were not included)2 Total number of patients on ventilators3 Total number of patients awaiting admission4 Waiting time for the last patient called in from wait-
ing room (Patient occupying ED bed waiting to beseen by the physician)
5 Longest time patient waiting for admission6 Number of beds in ED7 Number of total beds (occupied and vacant) in
hospitalThe first five variable objective measures were collectedsimultaneously and prospectively using a prepareddata sheet subsequently placed in a sealed box in EDThe ED attendance screen was printed at the same timeto check for the accuracy of data collection
The NEDOCS Calculating Tool amalgamated theseven objective data points for each time of data collec-tion and rated the data for that sample time on follow-ing scale 0ndash20
=
not busy 20ndash60
=
busy 60ndash100extremely busy but not overcrowded 100ndash140
=
overcrowded 140ndash180 severely overcrowded180ndash200
=
dangerously overcrowdedBeing a pilot study we aimed to duplicate Weissrsquos
sample method for the same time duration as in originalstudy
21
rather than calculate a new sample size How-ever we used different statistical analysis as we hadconcerns about the product moment correlation (
r
) coef-ficient used by Weiss The valid use of correlation coef-ficient requires a null hypothesis stating that there isno relationship between the two statistics This wouldnot be the case as both subjective and objective scoresare being collected at the same time to assess the samething that is lsquoovercrowdingrsquo In our pilot study theBlandndashAltman
2526
plot was chosen for statistical analy-sis to compensate for this error Differences betweenmeasurements within each pair were plotted on the
Y
-axis The averages of the two measurements were plot-ted on the
X
-axis The average was used as this wasthe closest estimate of the true result in the absence ofa gold standard for lsquoover-crowdingrsquo The mean differ-ence of all pairs was also calculated reflecting the
lsquoestimated biasrsquo or the systematic difference betweenthe two methods
Kappa statistics were used to analyse agreementbetween subjective and objective measures as well asassessment of interrater agreement on subjectiveresponses
Results
During the 3 week study period 2293 patients attendedthe ED an average of 109 patients per day For theentire 2004 calendar year the Ipswich Hospital ED aver-aged 115 patients per day
One hundred and twenty-eight sample times weredescribed by two scores (subjective and NEDOCS)over 3 weeks The datasets for the 3 week period werecomplete
Figure 1 shows a scatter diagram of transformedsubjective and objective (NEDOCS) scores Figure 2shows that the mean difference between the methods ofmeasurement is small (347 95 confidence interval[CI]
minus
0875ndash7878) Figure 2 also illustrates that therange of the 95 limits of agreement are wide (
minus
4652ndash5343)
The BlandndashAltman plot shows that in 5 of themeasurements one method of measurement is likely tobe more than 100-point raw score or 25 categoriesbeyond the other In the present study 16 pairs (125[95 CI 78ndash193]) had scores more than 40 points (onewhole category) apart and 49 pairs (38 [95 CI 30ndash469]) had scores in adjacent categories The kappavalue of 031 (95 CI 017ndash045) suggests poor agree-ment between the categorical scores
Interrater agreement of the subjective responses usedin the composite outcome score was high The intraclasscorrelation coefficient was 087 (95 CI 071ndash095) forthe question on lsquofeeling rushedrsquo For the lsquodegree of over-crowdingrsquo the intraclass correlation coefficient was 094(95 CI 082ndash097)
Discussion
The present study demonstrates that the NEDOCS toolcorrelated poorly with subjective clinician assessmentof overcrowding in our ED The poor correlation is veryobvious looking at Figure 2 The 95 limits of agree-ment are wide (more than two categories apart) makingthe NEDOCS tool imprecise when used in clinical set-ting Such imprecision is unacceptable if one is
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
285
considering up scaling hospital responses based purelyon the NEDOCS score In addition Figure 1 shows usthat there is no specific relationship between the NEDOCSand subjective scores These findings indicate that theNEDOCS tool is not ready to be used in Australia
Our findings might differ from Weissrsquos original studyfor several reasons The NEDOCS tool was developed
in the USA and might not be applicable in a regionalAustralian hospital with different patient flow andstaffing profile
The difference in findings may be partly explainedby our decision to use different statistical methodologyto Weiss and to interpretation of data results Weissused product moment correlation (
r
) coefficient for
Figure 1
Scatter diagram comparison of both raw scores (
) National Emergency Department Overcrowding Study (NEDOCS) andcomposite score
150
125
100
75
50
Com
posi
te_O
utco
me_
Var
iabl
e_S
core
25
00 25 50
NEDOCS_Score
75 100
Figure 2
BlandndashAltman plot
50
75
25
0
minus25
Diff
eren
ce b
etw
een
met
hods
minus75
minus50
0 25 50Average of both scores
75 100 125
95 confidence interval formean difference= minus0875 to 7828
95 limits of agreement= 5343 to minus4652
upper limit of agreement
mean diff =3476
lower limit of agreement
standard deviation = 2498
K Raj
et al
286
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
statistical analysis in their original study and the basisof its calculation may be questioned They concludedthat the NEDOCS score accurately reflects staffrsquos senseof lsquoovercrowdingrsquo quoting R
2
049 for the full model TheNEDOCS tool reflects the full model with 88 accuracyso it is even less accurate
Weiss quoted a high interrater agreement (correlationcoefficient 086ndash093) between physiciansrsquo and nursesrsquoLikert results and between each result and the averageas a justification for their use as composite outcomescore The Likert like scale used for subjective scoreswere developed from a preliminary survey of EDdirectors
22
who identified lack of ED beds ED closureand ambulance diversion patients managed in hall-ways full waiting rooms feeling lsquorushedrsquo and a wait ofgreater than 1 h to see a physician as evidence of EDovercrowding
The statistical analysis of the data where one mea-surement method (subjective score) is compared withanother measurement method (objective score) can befraught with danger When there is no gold standard tocompare the new measuring tool the statistical analysismust take into consideration the possible error of eachmethod For that reason we chose the BlandndashAltmanplot and subsequently demonstrated poor agreement
A review of the literature highlights the difficulty indefining overcrowding Hwang
et al
27
reviewed the lit-erature over 26 years and found a total of 230 articlesrelating to overcrowding in the ED including originalarticles reviews and editorials Only 23 of these hadexplicit definitions of overcrowding There was sub-stantial variation in the definition of lsquoovercrowding inthe EDrsquo within these articles The definitions focused onspecific issues like waiting time hospital-related butnon-ED factors or factors external to the hospital suchas ambulance diversions to describe overcrowding
There is little literature documenting quantitativemeasurements of overcrowding in the ED
2021
Bernstein
et al
developed the lsquoEmergency Department WorkIndexrsquo (EDWIN index) which included (i) number ofpatients in triage category (ii) triage category (iii)number of attending physicians on duty (iv) numberof treatment bays and (v) number of admitted patientsin ED The limitation of EDWIN index is that it is nota computer-based model It does not take into accountvarious other issues such as the role of a resident inED and also does not have any input from nursingstaff
Weiss
et al
2122
recognized this deficit in knowledgeand undertook the difficult but important task of devel-oping a computer-based objective model In its current
form this computer-based model NEDOCS tool has cor-related poorly with staffrsquos sense of overcrowding in ourhospital For the moment subjective assessment seemsto be the best method of assessing overcrowding untilwe find a better tool or refine the NEDOCS scoringmethod
The NEDOCS scoring method is easy simple andquick to use and could become a more important anduseful tool with further refinement A refined NEDOCStool may provide us with the definitions and scoringtool we need As Weiss suggests measurements thatinclude case mix within ED triage category and skillmix of staff may improve agreement between NEDOCSscore and staffrsquos perception of lsquoovercrowdingrsquo
There are several limitations to the present study Atno time during the study was the department severelyor dangerously overcrowded Correlation might bebetter or worse at these extreme times The study wasconducted at only one urban hospital ED with mixedchildren and adult presentations and might not be appli-cable to other systems or private ED The biggest lim-itation of the present study however is the lack of alsquogold standardrsquo by which to define ED overcrowdingWe chose to use subjective physiciannurse assessmentas the gold standard by which to measure the NEDOCStool It is possible that the NEDOCS tool might actuallybe very good and that staff subjective assessment isactually poor
Conclusion
The NEDOCS tool was not valid in our setting and hasbeen inconsistent in reflecting staffrsquos sense of lsquoover-crowdingrsquo for which it was primarily designedNEDOCS is still a potentially important tool worthy ofrefinement
Acknowledgements
I would like to acknowledge the assistance of all staffof the ED Ipswich General Hospital for helping to col-lect the data
Author contributions
KR conceived and designed the study collected the dataand wrote the manuscript KB assisted with some sta-tistics and manuscript editing SB and DM edited andassisted in writing the manuscript
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
287
Competing interests
None declared
Accepted 13 February 2006
References
1 Eisenberg D Woodbury R Willwerth J Brice LE Sieger MDonely M Critical condition
Time
2000
155
0040781X
2 Gibbs N Browning S Do you want to die
Time
1990
135
0040781X 90
3 Adrulis DP Kellrmann A Hintz E Hackman BB Weslowski VBEmergency departments and crowding in United States teachinghospitals
Ann Emerg Med
1991
20
980ndash60
4 Committee on Pediatric Emergency Medicine American acad-emy of pediatrics overcrowding crisis in our nationrsquos emergencydepartment is our safety net unraveling
Pediatrics
2004
114
878ndash88
5 Access block and overcrowding in emergency department Posi-tion paper Australian College for Emergency Medicine down-loaded on 2005 Available from URL httpwwwacemorgauopendocumentsaccessbookbackpdf [Accessed December2004]
6 Derlet RM Richards JR Overcrowding in the nations emergencydepartment complex causes and disturbing effects
Ann EmergMed
2000
35
63ndash8
7 Miro O Antonio MT Jimenez S
et al
Decreased health carequality associated with emergency department overcrowding
Eur J Emerg Med
1999
6
105ndash7
8 Fatovich DM Nagree Y Sprivulis P Access block causes emer-gency department overcrowding and ambulance diversion inPerth Western Australia
Emerg Med J
2005
22
351ndash4
9 Henson VL Vickey DL Patient self discharge from the emer-gency department who is at risk
Emerg Med J
2005
22
499ndash501
10 Fernandes CM Daya MR Barry S Palmer N Emergency depart-ment patients who leave without seeing a physician the TorontoHospital experience
Ann Emerg Med
1994
24
1092ndash6
11 Shaw KN Lavelle JM VESAS a solution to seasonal fluctuationsin emergency department census
Ann Emerg Med
1998
32
698ndash702
12 Saint Lamont S lsquoSee and Treatrsquo spreading like wildfire A qual-itative study into factors affecting its introduction and spread
Emerg Med J
2005
22
548ndash52
13 Anonymous To ease overcrowding delay elective surgeries
EdManag
2005
17
29ndash31
14 Anonymous Three strategies to reduce overcrowding
EdManag
2004
16
1ndash16
15 Anonymous Itrsquos not business as usual you can fight patientsurges with an aggressive plan
Ed Manag
2003
15
121ndash4
16 Kelen GD Scheulen JJ Hill PM Effect of an emergency depart-ment (ED) managed acute care unit on ED overcrowding andemergency medical services diversion
Acad Emerg Med
2001
8
1095ndash100
17 Lynn SG Kellermann A Critical decision making managing theemergency department in an overcrowded hospital
Ann EmergMed
1991
20
287ndash92
18 Reeder TJ Garrison HG When the safety net is unsafe real-timeassessment of the overcrowded emergency department
AcadEmerg Med
2001
8
1070ndash4
19 Wolff AM Bourke J Detecting and reducing adverse events inan Australian rural base hospital emergency department usingmedical screening and review
Emerg Med J
2002
19
35ndash40
20 Bernstein SL Verghese V Leung W Lunney AT Perez I Devel-opment and validation of a new index to measure emergencydepartment crowding
Acad Emerg Med
2003
10
938ndash42
21 Weiss SJ Derlet R Arnold J
et al
Estimating the degree ofemergency department overcrowding in academic medical cen-ters result of the National ED Overcrowding Study (NEDOCS)
Acad Emerg Med
2004
11
38ndash50
22 Weiss SJ Amdhal J Ernst AA Derlet R Richards J Nick TGDevelopment of site sampling form for evaluation of ED over-crowding
Med Sci Monit
2002
8
CR549ndash53
23 Weiss SJ Ernst AA Derlet R King R Bair A Nick TG Rela-tionship between the National ED Overcrowding Scale and thenumber of patients who leave without being seen in an academicED
Am J Emerg Med
2005
23
288ndash94
24 NECDOCS Calculating Tool Available from URL httphscunmeduemermednedocs_finshtml
25 Martin Bland J Altman DG Comparing methods of measure-ment why plotting difference against standard method is mis-leading
Lancet
1995
346
1085ndash7
26 Martin Bland J Altman DG Statistical method for assessingbetween two methods of clinical measurements
Lancet
1986
i
306ndash10
27 Hwang U Concato J Care in the emergency department howcrowded is overcrowded
Acad Emerg Med
2004
11
1097ndash101
Appendix I
Survey form for ED physician for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the opinion on lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy but not overcrowded4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
Please circle the opinion on lsquoFeeling rushedrsquo in ED1 2 3 4 5 61 = not rushed6 = rushed
K Raj et al
288 copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
After completing the survey form please place it intosealed box provided in Emergency DepartmentED emergency department NEDOCS National Emer-gency Department Over Crowding Study
Appendix II
Survey form for the charge nurse in ED for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
After completing the survey form please place it in thesealed box provided in Emergency DepartmentED emergency department NEDOCS NationalEmergency Department Over Crowding Study
K Raj
et al
284
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
Interrater agreement was tested retrospectively onthe composite outcome data collected in the first weekThe intraclass correlation coefficient was calculated forthe responses to the lsquofeeling rushedrsquo question askedfrom the doctors and then again for the lsquoovercrowdingrsquoquestion asked from the doctors and the charge nurse
The objective rating in each sample pair was calcu-lated by the Web-based NEDOCS Calculating Tool
24
using the following objective measurements1 Total number of patients in ED occupying beds
(Patients in waiting area were not included)2 Total number of patients on ventilators3 Total number of patients awaiting admission4 Waiting time for the last patient called in from wait-
ing room (Patient occupying ED bed waiting to beseen by the physician)
5 Longest time patient waiting for admission6 Number of beds in ED7 Number of total beds (occupied and vacant) in
hospitalThe first five variable objective measures were collectedsimultaneously and prospectively using a prepareddata sheet subsequently placed in a sealed box in EDThe ED attendance screen was printed at the same timeto check for the accuracy of data collection
The NEDOCS Calculating Tool amalgamated theseven objective data points for each time of data collec-tion and rated the data for that sample time on follow-ing scale 0ndash20
=
not busy 20ndash60
=
busy 60ndash100extremely busy but not overcrowded 100ndash140
=
overcrowded 140ndash180 severely overcrowded180ndash200
=
dangerously overcrowdedBeing a pilot study we aimed to duplicate Weissrsquos
sample method for the same time duration as in originalstudy
21
rather than calculate a new sample size How-ever we used different statistical analysis as we hadconcerns about the product moment correlation (
r
) coef-ficient used by Weiss The valid use of correlation coef-ficient requires a null hypothesis stating that there isno relationship between the two statistics This wouldnot be the case as both subjective and objective scoresare being collected at the same time to assess the samething that is lsquoovercrowdingrsquo In our pilot study theBlandndashAltman
2526
plot was chosen for statistical analy-sis to compensate for this error Differences betweenmeasurements within each pair were plotted on the
Y
-axis The averages of the two measurements were plot-ted on the
X
-axis The average was used as this wasthe closest estimate of the true result in the absence ofa gold standard for lsquoover-crowdingrsquo The mean differ-ence of all pairs was also calculated reflecting the
lsquoestimated biasrsquo or the systematic difference betweenthe two methods
Kappa statistics were used to analyse agreementbetween subjective and objective measures as well asassessment of interrater agreement on subjectiveresponses
Results
During the 3 week study period 2293 patients attendedthe ED an average of 109 patients per day For theentire 2004 calendar year the Ipswich Hospital ED aver-aged 115 patients per day
One hundred and twenty-eight sample times weredescribed by two scores (subjective and NEDOCS)over 3 weeks The datasets for the 3 week period werecomplete
Figure 1 shows a scatter diagram of transformedsubjective and objective (NEDOCS) scores Figure 2shows that the mean difference between the methods ofmeasurement is small (347 95 confidence interval[CI]
minus
0875ndash7878) Figure 2 also illustrates that therange of the 95 limits of agreement are wide (
minus
4652ndash5343)
The BlandndashAltman plot shows that in 5 of themeasurements one method of measurement is likely tobe more than 100-point raw score or 25 categoriesbeyond the other In the present study 16 pairs (125[95 CI 78ndash193]) had scores more than 40 points (onewhole category) apart and 49 pairs (38 [95 CI 30ndash469]) had scores in adjacent categories The kappavalue of 031 (95 CI 017ndash045) suggests poor agree-ment between the categorical scores
Interrater agreement of the subjective responses usedin the composite outcome score was high The intraclasscorrelation coefficient was 087 (95 CI 071ndash095) forthe question on lsquofeeling rushedrsquo For the lsquodegree of over-crowdingrsquo the intraclass correlation coefficient was 094(95 CI 082ndash097)
Discussion
The present study demonstrates that the NEDOCS toolcorrelated poorly with subjective clinician assessmentof overcrowding in our ED The poor correlation is veryobvious looking at Figure 2 The 95 limits of agree-ment are wide (more than two categories apart) makingthe NEDOCS tool imprecise when used in clinical set-ting Such imprecision is unacceptable if one is
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
285
considering up scaling hospital responses based purelyon the NEDOCS score In addition Figure 1 shows usthat there is no specific relationship between the NEDOCSand subjective scores These findings indicate that theNEDOCS tool is not ready to be used in Australia
Our findings might differ from Weissrsquos original studyfor several reasons The NEDOCS tool was developed
in the USA and might not be applicable in a regionalAustralian hospital with different patient flow andstaffing profile
The difference in findings may be partly explainedby our decision to use different statistical methodologyto Weiss and to interpretation of data results Weissused product moment correlation (
r
) coefficient for
Figure 1
Scatter diagram comparison of both raw scores (
) National Emergency Department Overcrowding Study (NEDOCS) andcomposite score
150
125
100
75
50
Com
posi
te_O
utco
me_
Var
iabl
e_S
core
25
00 25 50
NEDOCS_Score
75 100
Figure 2
BlandndashAltman plot
50
75
25
0
minus25
Diff
eren
ce b
etw
een
met
hods
minus75
minus50
0 25 50Average of both scores
75 100 125
95 confidence interval formean difference= minus0875 to 7828
95 limits of agreement= 5343 to minus4652
upper limit of agreement
mean diff =3476
lower limit of agreement
standard deviation = 2498
K Raj
et al
286
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
statistical analysis in their original study and the basisof its calculation may be questioned They concludedthat the NEDOCS score accurately reflects staffrsquos senseof lsquoovercrowdingrsquo quoting R
2
049 for the full model TheNEDOCS tool reflects the full model with 88 accuracyso it is even less accurate
Weiss quoted a high interrater agreement (correlationcoefficient 086ndash093) between physiciansrsquo and nursesrsquoLikert results and between each result and the averageas a justification for their use as composite outcomescore The Likert like scale used for subjective scoreswere developed from a preliminary survey of EDdirectors
22
who identified lack of ED beds ED closureand ambulance diversion patients managed in hall-ways full waiting rooms feeling lsquorushedrsquo and a wait ofgreater than 1 h to see a physician as evidence of EDovercrowding
The statistical analysis of the data where one mea-surement method (subjective score) is compared withanother measurement method (objective score) can befraught with danger When there is no gold standard tocompare the new measuring tool the statistical analysismust take into consideration the possible error of eachmethod For that reason we chose the BlandndashAltmanplot and subsequently demonstrated poor agreement
A review of the literature highlights the difficulty indefining overcrowding Hwang
et al
27
reviewed the lit-erature over 26 years and found a total of 230 articlesrelating to overcrowding in the ED including originalarticles reviews and editorials Only 23 of these hadexplicit definitions of overcrowding There was sub-stantial variation in the definition of lsquoovercrowding inthe EDrsquo within these articles The definitions focused onspecific issues like waiting time hospital-related butnon-ED factors or factors external to the hospital suchas ambulance diversions to describe overcrowding
There is little literature documenting quantitativemeasurements of overcrowding in the ED
2021
Bernstein
et al
developed the lsquoEmergency Department WorkIndexrsquo (EDWIN index) which included (i) number ofpatients in triage category (ii) triage category (iii)number of attending physicians on duty (iv) numberof treatment bays and (v) number of admitted patientsin ED The limitation of EDWIN index is that it is nota computer-based model It does not take into accountvarious other issues such as the role of a resident inED and also does not have any input from nursingstaff
Weiss
et al
2122
recognized this deficit in knowledgeand undertook the difficult but important task of devel-oping a computer-based objective model In its current
form this computer-based model NEDOCS tool has cor-related poorly with staffrsquos sense of overcrowding in ourhospital For the moment subjective assessment seemsto be the best method of assessing overcrowding untilwe find a better tool or refine the NEDOCS scoringmethod
The NEDOCS scoring method is easy simple andquick to use and could become a more important anduseful tool with further refinement A refined NEDOCStool may provide us with the definitions and scoringtool we need As Weiss suggests measurements thatinclude case mix within ED triage category and skillmix of staff may improve agreement between NEDOCSscore and staffrsquos perception of lsquoovercrowdingrsquo
There are several limitations to the present study Atno time during the study was the department severelyor dangerously overcrowded Correlation might bebetter or worse at these extreme times The study wasconducted at only one urban hospital ED with mixedchildren and adult presentations and might not be appli-cable to other systems or private ED The biggest lim-itation of the present study however is the lack of alsquogold standardrsquo by which to define ED overcrowdingWe chose to use subjective physiciannurse assessmentas the gold standard by which to measure the NEDOCStool It is possible that the NEDOCS tool might actuallybe very good and that staff subjective assessment isactually poor
Conclusion
The NEDOCS tool was not valid in our setting and hasbeen inconsistent in reflecting staffrsquos sense of lsquoover-crowdingrsquo for which it was primarily designedNEDOCS is still a potentially important tool worthy ofrefinement
Acknowledgements
I would like to acknowledge the assistance of all staffof the ED Ipswich General Hospital for helping to col-lect the data
Author contributions
KR conceived and designed the study collected the dataand wrote the manuscript KB assisted with some sta-tistics and manuscript editing SB and DM edited andassisted in writing the manuscript
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
287
Competing interests
None declared
Accepted 13 February 2006
References
1 Eisenberg D Woodbury R Willwerth J Brice LE Sieger MDonely M Critical condition
Time
2000
155
0040781X
2 Gibbs N Browning S Do you want to die
Time
1990
135
0040781X 90
3 Adrulis DP Kellrmann A Hintz E Hackman BB Weslowski VBEmergency departments and crowding in United States teachinghospitals
Ann Emerg Med
1991
20
980ndash60
4 Committee on Pediatric Emergency Medicine American acad-emy of pediatrics overcrowding crisis in our nationrsquos emergencydepartment is our safety net unraveling
Pediatrics
2004
114
878ndash88
5 Access block and overcrowding in emergency department Posi-tion paper Australian College for Emergency Medicine down-loaded on 2005 Available from URL httpwwwacemorgauopendocumentsaccessbookbackpdf [Accessed December2004]
6 Derlet RM Richards JR Overcrowding in the nations emergencydepartment complex causes and disturbing effects
Ann EmergMed
2000
35
63ndash8
7 Miro O Antonio MT Jimenez S
et al
Decreased health carequality associated with emergency department overcrowding
Eur J Emerg Med
1999
6
105ndash7
8 Fatovich DM Nagree Y Sprivulis P Access block causes emer-gency department overcrowding and ambulance diversion inPerth Western Australia
Emerg Med J
2005
22
351ndash4
9 Henson VL Vickey DL Patient self discharge from the emer-gency department who is at risk
Emerg Med J
2005
22
499ndash501
10 Fernandes CM Daya MR Barry S Palmer N Emergency depart-ment patients who leave without seeing a physician the TorontoHospital experience
Ann Emerg Med
1994
24
1092ndash6
11 Shaw KN Lavelle JM VESAS a solution to seasonal fluctuationsin emergency department census
Ann Emerg Med
1998
32
698ndash702
12 Saint Lamont S lsquoSee and Treatrsquo spreading like wildfire A qual-itative study into factors affecting its introduction and spread
Emerg Med J
2005
22
548ndash52
13 Anonymous To ease overcrowding delay elective surgeries
EdManag
2005
17
29ndash31
14 Anonymous Three strategies to reduce overcrowding
EdManag
2004
16
1ndash16
15 Anonymous Itrsquos not business as usual you can fight patientsurges with an aggressive plan
Ed Manag
2003
15
121ndash4
16 Kelen GD Scheulen JJ Hill PM Effect of an emergency depart-ment (ED) managed acute care unit on ED overcrowding andemergency medical services diversion
Acad Emerg Med
2001
8
1095ndash100
17 Lynn SG Kellermann A Critical decision making managing theemergency department in an overcrowded hospital
Ann EmergMed
1991
20
287ndash92
18 Reeder TJ Garrison HG When the safety net is unsafe real-timeassessment of the overcrowded emergency department
AcadEmerg Med
2001
8
1070ndash4
19 Wolff AM Bourke J Detecting and reducing adverse events inan Australian rural base hospital emergency department usingmedical screening and review
Emerg Med J
2002
19
35ndash40
20 Bernstein SL Verghese V Leung W Lunney AT Perez I Devel-opment and validation of a new index to measure emergencydepartment crowding
Acad Emerg Med
2003
10
938ndash42
21 Weiss SJ Derlet R Arnold J
et al
Estimating the degree ofemergency department overcrowding in academic medical cen-ters result of the National ED Overcrowding Study (NEDOCS)
Acad Emerg Med
2004
11
38ndash50
22 Weiss SJ Amdhal J Ernst AA Derlet R Richards J Nick TGDevelopment of site sampling form for evaluation of ED over-crowding
Med Sci Monit
2002
8
CR549ndash53
23 Weiss SJ Ernst AA Derlet R King R Bair A Nick TG Rela-tionship between the National ED Overcrowding Scale and thenumber of patients who leave without being seen in an academicED
Am J Emerg Med
2005
23
288ndash94
24 NECDOCS Calculating Tool Available from URL httphscunmeduemermednedocs_finshtml
25 Martin Bland J Altman DG Comparing methods of measure-ment why plotting difference against standard method is mis-leading
Lancet
1995
346
1085ndash7
26 Martin Bland J Altman DG Statistical method for assessingbetween two methods of clinical measurements
Lancet
1986
i
306ndash10
27 Hwang U Concato J Care in the emergency department howcrowded is overcrowded
Acad Emerg Med
2004
11
1097ndash101
Appendix I
Survey form for ED physician for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the opinion on lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy but not overcrowded4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
Please circle the opinion on lsquoFeeling rushedrsquo in ED1 2 3 4 5 61 = not rushed6 = rushed
K Raj et al
288 copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
After completing the survey form please place it intosealed box provided in Emergency DepartmentED emergency department NEDOCS National Emer-gency Department Over Crowding Study
Appendix II
Survey form for the charge nurse in ED for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
After completing the survey form please place it in thesealed box provided in Emergency DepartmentED emergency department NEDOCS NationalEmergency Department Over Crowding Study
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
285
considering up scaling hospital responses based purelyon the NEDOCS score In addition Figure 1 shows usthat there is no specific relationship between the NEDOCSand subjective scores These findings indicate that theNEDOCS tool is not ready to be used in Australia
Our findings might differ from Weissrsquos original studyfor several reasons The NEDOCS tool was developed
in the USA and might not be applicable in a regionalAustralian hospital with different patient flow andstaffing profile
The difference in findings may be partly explainedby our decision to use different statistical methodologyto Weiss and to interpretation of data results Weissused product moment correlation (
r
) coefficient for
Figure 1
Scatter diagram comparison of both raw scores (
) National Emergency Department Overcrowding Study (NEDOCS) andcomposite score
150
125
100
75
50
Com
posi
te_O
utco
me_
Var
iabl
e_S
core
25
00 25 50
NEDOCS_Score
75 100
Figure 2
BlandndashAltman plot
50
75
25
0
minus25
Diff
eren
ce b
etw
een
met
hods
minus75
minus50
0 25 50Average of both scores
75 100 125
95 confidence interval formean difference= minus0875 to 7828
95 limits of agreement= 5343 to minus4652
upper limit of agreement
mean diff =3476
lower limit of agreement
standard deviation = 2498
K Raj
et al
286
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
statistical analysis in their original study and the basisof its calculation may be questioned They concludedthat the NEDOCS score accurately reflects staffrsquos senseof lsquoovercrowdingrsquo quoting R
2
049 for the full model TheNEDOCS tool reflects the full model with 88 accuracyso it is even less accurate
Weiss quoted a high interrater agreement (correlationcoefficient 086ndash093) between physiciansrsquo and nursesrsquoLikert results and between each result and the averageas a justification for their use as composite outcomescore The Likert like scale used for subjective scoreswere developed from a preliminary survey of EDdirectors
22
who identified lack of ED beds ED closureand ambulance diversion patients managed in hall-ways full waiting rooms feeling lsquorushedrsquo and a wait ofgreater than 1 h to see a physician as evidence of EDovercrowding
The statistical analysis of the data where one mea-surement method (subjective score) is compared withanother measurement method (objective score) can befraught with danger When there is no gold standard tocompare the new measuring tool the statistical analysismust take into consideration the possible error of eachmethod For that reason we chose the BlandndashAltmanplot and subsequently demonstrated poor agreement
A review of the literature highlights the difficulty indefining overcrowding Hwang
et al
27
reviewed the lit-erature over 26 years and found a total of 230 articlesrelating to overcrowding in the ED including originalarticles reviews and editorials Only 23 of these hadexplicit definitions of overcrowding There was sub-stantial variation in the definition of lsquoovercrowding inthe EDrsquo within these articles The definitions focused onspecific issues like waiting time hospital-related butnon-ED factors or factors external to the hospital suchas ambulance diversions to describe overcrowding
There is little literature documenting quantitativemeasurements of overcrowding in the ED
2021
Bernstein
et al
developed the lsquoEmergency Department WorkIndexrsquo (EDWIN index) which included (i) number ofpatients in triage category (ii) triage category (iii)number of attending physicians on duty (iv) numberof treatment bays and (v) number of admitted patientsin ED The limitation of EDWIN index is that it is nota computer-based model It does not take into accountvarious other issues such as the role of a resident inED and also does not have any input from nursingstaff
Weiss
et al
2122
recognized this deficit in knowledgeand undertook the difficult but important task of devel-oping a computer-based objective model In its current
form this computer-based model NEDOCS tool has cor-related poorly with staffrsquos sense of overcrowding in ourhospital For the moment subjective assessment seemsto be the best method of assessing overcrowding untilwe find a better tool or refine the NEDOCS scoringmethod
The NEDOCS scoring method is easy simple andquick to use and could become a more important anduseful tool with further refinement A refined NEDOCStool may provide us with the definitions and scoringtool we need As Weiss suggests measurements thatinclude case mix within ED triage category and skillmix of staff may improve agreement between NEDOCSscore and staffrsquos perception of lsquoovercrowdingrsquo
There are several limitations to the present study Atno time during the study was the department severelyor dangerously overcrowded Correlation might bebetter or worse at these extreme times The study wasconducted at only one urban hospital ED with mixedchildren and adult presentations and might not be appli-cable to other systems or private ED The biggest lim-itation of the present study however is the lack of alsquogold standardrsquo by which to define ED overcrowdingWe chose to use subjective physiciannurse assessmentas the gold standard by which to measure the NEDOCStool It is possible that the NEDOCS tool might actuallybe very good and that staff subjective assessment isactually poor
Conclusion
The NEDOCS tool was not valid in our setting and hasbeen inconsistent in reflecting staffrsquos sense of lsquoover-crowdingrsquo for which it was primarily designedNEDOCS is still a potentially important tool worthy ofrefinement
Acknowledgements
I would like to acknowledge the assistance of all staffof the ED Ipswich General Hospital for helping to col-lect the data
Author contributions
KR conceived and designed the study collected the dataand wrote the manuscript KB assisted with some sta-tistics and manuscript editing SB and DM edited andassisted in writing the manuscript
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
287
Competing interests
None declared
Accepted 13 February 2006
References
1 Eisenberg D Woodbury R Willwerth J Brice LE Sieger MDonely M Critical condition
Time
2000
155
0040781X
2 Gibbs N Browning S Do you want to die
Time
1990
135
0040781X 90
3 Adrulis DP Kellrmann A Hintz E Hackman BB Weslowski VBEmergency departments and crowding in United States teachinghospitals
Ann Emerg Med
1991
20
980ndash60
4 Committee on Pediatric Emergency Medicine American acad-emy of pediatrics overcrowding crisis in our nationrsquos emergencydepartment is our safety net unraveling
Pediatrics
2004
114
878ndash88
5 Access block and overcrowding in emergency department Posi-tion paper Australian College for Emergency Medicine down-loaded on 2005 Available from URL httpwwwacemorgauopendocumentsaccessbookbackpdf [Accessed December2004]
6 Derlet RM Richards JR Overcrowding in the nations emergencydepartment complex causes and disturbing effects
Ann EmergMed
2000
35
63ndash8
7 Miro O Antonio MT Jimenez S
et al
Decreased health carequality associated with emergency department overcrowding
Eur J Emerg Med
1999
6
105ndash7
8 Fatovich DM Nagree Y Sprivulis P Access block causes emer-gency department overcrowding and ambulance diversion inPerth Western Australia
Emerg Med J
2005
22
351ndash4
9 Henson VL Vickey DL Patient self discharge from the emer-gency department who is at risk
Emerg Med J
2005
22
499ndash501
10 Fernandes CM Daya MR Barry S Palmer N Emergency depart-ment patients who leave without seeing a physician the TorontoHospital experience
Ann Emerg Med
1994
24
1092ndash6
11 Shaw KN Lavelle JM VESAS a solution to seasonal fluctuationsin emergency department census
Ann Emerg Med
1998
32
698ndash702
12 Saint Lamont S lsquoSee and Treatrsquo spreading like wildfire A qual-itative study into factors affecting its introduction and spread
Emerg Med J
2005
22
548ndash52
13 Anonymous To ease overcrowding delay elective surgeries
EdManag
2005
17
29ndash31
14 Anonymous Three strategies to reduce overcrowding
EdManag
2004
16
1ndash16
15 Anonymous Itrsquos not business as usual you can fight patientsurges with an aggressive plan
Ed Manag
2003
15
121ndash4
16 Kelen GD Scheulen JJ Hill PM Effect of an emergency depart-ment (ED) managed acute care unit on ED overcrowding andemergency medical services diversion
Acad Emerg Med
2001
8
1095ndash100
17 Lynn SG Kellermann A Critical decision making managing theemergency department in an overcrowded hospital
Ann EmergMed
1991
20
287ndash92
18 Reeder TJ Garrison HG When the safety net is unsafe real-timeassessment of the overcrowded emergency department
AcadEmerg Med
2001
8
1070ndash4
19 Wolff AM Bourke J Detecting and reducing adverse events inan Australian rural base hospital emergency department usingmedical screening and review
Emerg Med J
2002
19
35ndash40
20 Bernstein SL Verghese V Leung W Lunney AT Perez I Devel-opment and validation of a new index to measure emergencydepartment crowding
Acad Emerg Med
2003
10
938ndash42
21 Weiss SJ Derlet R Arnold J
et al
Estimating the degree ofemergency department overcrowding in academic medical cen-ters result of the National ED Overcrowding Study (NEDOCS)
Acad Emerg Med
2004
11
38ndash50
22 Weiss SJ Amdhal J Ernst AA Derlet R Richards J Nick TGDevelopment of site sampling form for evaluation of ED over-crowding
Med Sci Monit
2002
8
CR549ndash53
23 Weiss SJ Ernst AA Derlet R King R Bair A Nick TG Rela-tionship between the National ED Overcrowding Scale and thenumber of patients who leave without being seen in an academicED
Am J Emerg Med
2005
23
288ndash94
24 NECDOCS Calculating Tool Available from URL httphscunmeduemermednedocs_finshtml
25 Martin Bland J Altman DG Comparing methods of measure-ment why plotting difference against standard method is mis-leading
Lancet
1995
346
1085ndash7
26 Martin Bland J Altman DG Statistical method for assessingbetween two methods of clinical measurements
Lancet
1986
i
306ndash10
27 Hwang U Concato J Care in the emergency department howcrowded is overcrowded
Acad Emerg Med
2004
11
1097ndash101
Appendix I
Survey form for ED physician for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the opinion on lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy but not overcrowded4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
Please circle the opinion on lsquoFeeling rushedrsquo in ED1 2 3 4 5 61 = not rushed6 = rushed
K Raj et al
288 copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
After completing the survey form please place it intosealed box provided in Emergency DepartmentED emergency department NEDOCS National Emer-gency Department Over Crowding Study
Appendix II
Survey form for the charge nurse in ED for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
After completing the survey form please place it in thesealed box provided in Emergency DepartmentED emergency department NEDOCS NationalEmergency Department Over Crowding Study
K Raj
et al
286
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
statistical analysis in their original study and the basisof its calculation may be questioned They concludedthat the NEDOCS score accurately reflects staffrsquos senseof lsquoovercrowdingrsquo quoting R
2
049 for the full model TheNEDOCS tool reflects the full model with 88 accuracyso it is even less accurate
Weiss quoted a high interrater agreement (correlationcoefficient 086ndash093) between physiciansrsquo and nursesrsquoLikert results and between each result and the averageas a justification for their use as composite outcomescore The Likert like scale used for subjective scoreswere developed from a preliminary survey of EDdirectors
22
who identified lack of ED beds ED closureand ambulance diversion patients managed in hall-ways full waiting rooms feeling lsquorushedrsquo and a wait ofgreater than 1 h to see a physician as evidence of EDovercrowding
The statistical analysis of the data where one mea-surement method (subjective score) is compared withanother measurement method (objective score) can befraught with danger When there is no gold standard tocompare the new measuring tool the statistical analysismust take into consideration the possible error of eachmethod For that reason we chose the BlandndashAltmanplot and subsequently demonstrated poor agreement
A review of the literature highlights the difficulty indefining overcrowding Hwang
et al
27
reviewed the lit-erature over 26 years and found a total of 230 articlesrelating to overcrowding in the ED including originalarticles reviews and editorials Only 23 of these hadexplicit definitions of overcrowding There was sub-stantial variation in the definition of lsquoovercrowding inthe EDrsquo within these articles The definitions focused onspecific issues like waiting time hospital-related butnon-ED factors or factors external to the hospital suchas ambulance diversions to describe overcrowding
There is little literature documenting quantitativemeasurements of overcrowding in the ED
2021
Bernstein
et al
developed the lsquoEmergency Department WorkIndexrsquo (EDWIN index) which included (i) number ofpatients in triage category (ii) triage category (iii)number of attending physicians on duty (iv) numberof treatment bays and (v) number of admitted patientsin ED The limitation of EDWIN index is that it is nota computer-based model It does not take into accountvarious other issues such as the role of a resident inED and also does not have any input from nursingstaff
Weiss
et al
2122
recognized this deficit in knowledgeand undertook the difficult but important task of devel-oping a computer-based objective model In its current
form this computer-based model NEDOCS tool has cor-related poorly with staffrsquos sense of overcrowding in ourhospital For the moment subjective assessment seemsto be the best method of assessing overcrowding untilwe find a better tool or refine the NEDOCS scoringmethod
The NEDOCS scoring method is easy simple andquick to use and could become a more important anduseful tool with further refinement A refined NEDOCStool may provide us with the definitions and scoringtool we need As Weiss suggests measurements thatinclude case mix within ED triage category and skillmix of staff may improve agreement between NEDOCSscore and staffrsquos perception of lsquoovercrowdingrsquo
There are several limitations to the present study Atno time during the study was the department severelyor dangerously overcrowded Correlation might bebetter or worse at these extreme times The study wasconducted at only one urban hospital ED with mixedchildren and adult presentations and might not be appli-cable to other systems or private ED The biggest lim-itation of the present study however is the lack of alsquogold standardrsquo by which to define ED overcrowdingWe chose to use subjective physiciannurse assessmentas the gold standard by which to measure the NEDOCStool It is possible that the NEDOCS tool might actuallybe very good and that staff subjective assessment isactually poor
Conclusion
The NEDOCS tool was not valid in our setting and hasbeen inconsistent in reflecting staffrsquos sense of lsquoover-crowdingrsquo for which it was primarily designedNEDOCS is still a potentially important tool worthy ofrefinement
Acknowledgements
I would like to acknowledge the assistance of all staffof the ED Ipswich General Hospital for helping to col-lect the data
Author contributions
KR conceived and designed the study collected the dataand wrote the manuscript KB assisted with some sta-tistics and manuscript editing SB and DM edited andassisted in writing the manuscript
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
287
Competing interests
None declared
Accepted 13 February 2006
References
1 Eisenberg D Woodbury R Willwerth J Brice LE Sieger MDonely M Critical condition
Time
2000
155
0040781X
2 Gibbs N Browning S Do you want to die
Time
1990
135
0040781X 90
3 Adrulis DP Kellrmann A Hintz E Hackman BB Weslowski VBEmergency departments and crowding in United States teachinghospitals
Ann Emerg Med
1991
20
980ndash60
4 Committee on Pediatric Emergency Medicine American acad-emy of pediatrics overcrowding crisis in our nationrsquos emergencydepartment is our safety net unraveling
Pediatrics
2004
114
878ndash88
5 Access block and overcrowding in emergency department Posi-tion paper Australian College for Emergency Medicine down-loaded on 2005 Available from URL httpwwwacemorgauopendocumentsaccessbookbackpdf [Accessed December2004]
6 Derlet RM Richards JR Overcrowding in the nations emergencydepartment complex causes and disturbing effects
Ann EmergMed
2000
35
63ndash8
7 Miro O Antonio MT Jimenez S
et al
Decreased health carequality associated with emergency department overcrowding
Eur J Emerg Med
1999
6
105ndash7
8 Fatovich DM Nagree Y Sprivulis P Access block causes emer-gency department overcrowding and ambulance diversion inPerth Western Australia
Emerg Med J
2005
22
351ndash4
9 Henson VL Vickey DL Patient self discharge from the emer-gency department who is at risk
Emerg Med J
2005
22
499ndash501
10 Fernandes CM Daya MR Barry S Palmer N Emergency depart-ment patients who leave without seeing a physician the TorontoHospital experience
Ann Emerg Med
1994
24
1092ndash6
11 Shaw KN Lavelle JM VESAS a solution to seasonal fluctuationsin emergency department census
Ann Emerg Med
1998
32
698ndash702
12 Saint Lamont S lsquoSee and Treatrsquo spreading like wildfire A qual-itative study into factors affecting its introduction and spread
Emerg Med J
2005
22
548ndash52
13 Anonymous To ease overcrowding delay elective surgeries
EdManag
2005
17
29ndash31
14 Anonymous Three strategies to reduce overcrowding
EdManag
2004
16
1ndash16
15 Anonymous Itrsquos not business as usual you can fight patientsurges with an aggressive plan
Ed Manag
2003
15
121ndash4
16 Kelen GD Scheulen JJ Hill PM Effect of an emergency depart-ment (ED) managed acute care unit on ED overcrowding andemergency medical services diversion
Acad Emerg Med
2001
8
1095ndash100
17 Lynn SG Kellermann A Critical decision making managing theemergency department in an overcrowded hospital
Ann EmergMed
1991
20
287ndash92
18 Reeder TJ Garrison HG When the safety net is unsafe real-timeassessment of the overcrowded emergency department
AcadEmerg Med
2001
8
1070ndash4
19 Wolff AM Bourke J Detecting and reducing adverse events inan Australian rural base hospital emergency department usingmedical screening and review
Emerg Med J
2002
19
35ndash40
20 Bernstein SL Verghese V Leung W Lunney AT Perez I Devel-opment and validation of a new index to measure emergencydepartment crowding
Acad Emerg Med
2003
10
938ndash42
21 Weiss SJ Derlet R Arnold J
et al
Estimating the degree ofemergency department overcrowding in academic medical cen-ters result of the National ED Overcrowding Study (NEDOCS)
Acad Emerg Med
2004
11
38ndash50
22 Weiss SJ Amdhal J Ernst AA Derlet R Richards J Nick TGDevelopment of site sampling form for evaluation of ED over-crowding
Med Sci Monit
2002
8
CR549ndash53
23 Weiss SJ Ernst AA Derlet R King R Bair A Nick TG Rela-tionship between the National ED Overcrowding Scale and thenumber of patients who leave without being seen in an academicED
Am J Emerg Med
2005
23
288ndash94
24 NECDOCS Calculating Tool Available from URL httphscunmeduemermednedocs_finshtml
25 Martin Bland J Altman DG Comparing methods of measure-ment why plotting difference against standard method is mis-leading
Lancet
1995
346
1085ndash7
26 Martin Bland J Altman DG Statistical method for assessingbetween two methods of clinical measurements
Lancet
1986
i
306ndash10
27 Hwang U Concato J Care in the emergency department howcrowded is overcrowded
Acad Emerg Med
2004
11
1097ndash101
Appendix I
Survey form for ED physician for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the opinion on lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy but not overcrowded4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
Please circle the opinion on lsquoFeeling rushedrsquo in ED1 2 3 4 5 61 = not rushed6 = rushed
K Raj et al
288 copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
After completing the survey form please place it intosealed box provided in Emergency DepartmentED emergency department NEDOCS National Emer-gency Department Over Crowding Study
Appendix II
Survey form for the charge nurse in ED for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
After completing the survey form please place it in thesealed box provided in Emergency DepartmentED emergency department NEDOCS NationalEmergency Department Over Crowding Study
Web based ED overcrowding assessment
copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
287
Competing interests
None declared
Accepted 13 February 2006
References
1 Eisenberg D Woodbury R Willwerth J Brice LE Sieger MDonely M Critical condition
Time
2000
155
0040781X
2 Gibbs N Browning S Do you want to die
Time
1990
135
0040781X 90
3 Adrulis DP Kellrmann A Hintz E Hackman BB Weslowski VBEmergency departments and crowding in United States teachinghospitals
Ann Emerg Med
1991
20
980ndash60
4 Committee on Pediatric Emergency Medicine American acad-emy of pediatrics overcrowding crisis in our nationrsquos emergencydepartment is our safety net unraveling
Pediatrics
2004
114
878ndash88
5 Access block and overcrowding in emergency department Posi-tion paper Australian College for Emergency Medicine down-loaded on 2005 Available from URL httpwwwacemorgauopendocumentsaccessbookbackpdf [Accessed December2004]
6 Derlet RM Richards JR Overcrowding in the nations emergencydepartment complex causes and disturbing effects
Ann EmergMed
2000
35
63ndash8
7 Miro O Antonio MT Jimenez S
et al
Decreased health carequality associated with emergency department overcrowding
Eur J Emerg Med
1999
6
105ndash7
8 Fatovich DM Nagree Y Sprivulis P Access block causes emer-gency department overcrowding and ambulance diversion inPerth Western Australia
Emerg Med J
2005
22
351ndash4
9 Henson VL Vickey DL Patient self discharge from the emer-gency department who is at risk
Emerg Med J
2005
22
499ndash501
10 Fernandes CM Daya MR Barry S Palmer N Emergency depart-ment patients who leave without seeing a physician the TorontoHospital experience
Ann Emerg Med
1994
24
1092ndash6
11 Shaw KN Lavelle JM VESAS a solution to seasonal fluctuationsin emergency department census
Ann Emerg Med
1998
32
698ndash702
12 Saint Lamont S lsquoSee and Treatrsquo spreading like wildfire A qual-itative study into factors affecting its introduction and spread
Emerg Med J
2005
22
548ndash52
13 Anonymous To ease overcrowding delay elective surgeries
EdManag
2005
17
29ndash31
14 Anonymous Three strategies to reduce overcrowding
EdManag
2004
16
1ndash16
15 Anonymous Itrsquos not business as usual you can fight patientsurges with an aggressive plan
Ed Manag
2003
15
121ndash4
16 Kelen GD Scheulen JJ Hill PM Effect of an emergency depart-ment (ED) managed acute care unit on ED overcrowding andemergency medical services diversion
Acad Emerg Med
2001
8
1095ndash100
17 Lynn SG Kellermann A Critical decision making managing theemergency department in an overcrowded hospital
Ann EmergMed
1991
20
287ndash92
18 Reeder TJ Garrison HG When the safety net is unsafe real-timeassessment of the overcrowded emergency department
AcadEmerg Med
2001
8
1070ndash4
19 Wolff AM Bourke J Detecting and reducing adverse events inan Australian rural base hospital emergency department usingmedical screening and review
Emerg Med J
2002
19
35ndash40
20 Bernstein SL Verghese V Leung W Lunney AT Perez I Devel-opment and validation of a new index to measure emergencydepartment crowding
Acad Emerg Med
2003
10
938ndash42
21 Weiss SJ Derlet R Arnold J
et al
Estimating the degree ofemergency department overcrowding in academic medical cen-ters result of the National ED Overcrowding Study (NEDOCS)
Acad Emerg Med
2004
11
38ndash50
22 Weiss SJ Amdhal J Ernst AA Derlet R Richards J Nick TGDevelopment of site sampling form for evaluation of ED over-crowding
Med Sci Monit
2002
8
CR549ndash53
23 Weiss SJ Ernst AA Derlet R King R Bair A Nick TG Rela-tionship between the National ED Overcrowding Scale and thenumber of patients who leave without being seen in an academicED
Am J Emerg Med
2005
23
288ndash94
24 NECDOCS Calculating Tool Available from URL httphscunmeduemermednedocs_finshtml
25 Martin Bland J Altman DG Comparing methods of measure-ment why plotting difference against standard method is mis-leading
Lancet
1995
346
1085ndash7
26 Martin Bland J Altman DG Statistical method for assessingbetween two methods of clinical measurements
Lancet
1986
i
306ndash10
27 Hwang U Concato J Care in the emergency department howcrowded is overcrowded
Acad Emerg Med
2004
11
1097ndash101
Appendix I
Survey form for ED physician for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the opinion on lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy but not overcrowded4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
Please circle the opinion on lsquoFeeling rushedrsquo in ED1 2 3 4 5 61 = not rushed6 = rushed
K Raj et al
288 copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
After completing the survey form please place it intosealed box provided in Emergency DepartmentED emergency department NEDOCS National Emer-gency Department Over Crowding Study
Appendix II
Survey form for the charge nurse in ED for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
After completing the survey form please place it in thesealed box provided in Emergency DepartmentED emergency department NEDOCS NationalEmergency Department Over Crowding Study
K Raj et al
288 copy 2006 The AuthorsJournal compilation copy 2006 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine
After completing the survey form please place it intosealed box provided in Emergency DepartmentED emergency department NEDOCS National Emer-gency Department Over Crowding Study
Appendix II
Survey form for the charge nurse in ED for NEDOCS tool
DatePlease circle the timeTime 1 AM 5 AM 9 AM 1 PM 5 PM 9 PM
Please circle the lsquoDegree of Overcrowdingrsquo1 2 3 4 5 61 = not busy2 = busy3 = extremely busy4 = overcrowded5 = severely overcrowded6 = dangerously overcrowded
After completing the survey form please place it in thesealed box provided in Emergency DepartmentED emergency department NEDOCS NationalEmergency Department Over Crowding Study