Staffing, Capacity, and Ambulance Diversion in Emergency Departments: United States, 2003–04

24 Pages·2006·1.2 MB·English

Number 376 + September 27, 2006
Staffing, Capacity, and Ambulance Diversion in
Emergency Departments: United States, 2003–04
by Catharine W. Burt, Ed.D., and Linda F. McCaig, M.P.H., Division of Health Care Statistics
Abstract Introduction
Objective—The increased demand for emergency department (ED) services In recent years, growth in the use of
over the past decade has resulted in crowding. This report presents estimates of hospital emergency medical services
structure and process characteristics of hospital EDs related to their capacity to treat (EMS) has coincided with a decline in
medical and surgical emergencies. Estimates of EDs experiencing crowded the number of EDs, leading to concerns
conditions are also presented. about the capacity of EDs that continue
Methods—Several facility supplements were added to the 2003–04 National to operate. The annual number of ED
HospitalAmbulatory Medical Care Survey (NHAMCS), which were completed by visits in the United States rose by 18%
hospital staff. NHAMCS samples nonfederal, short-stay, and general hospitals in the between 1994 and 2004 (from 93
United States. Of all sample hospitals that operated 24-hour EDs, 83percent million to 110 million), whereas the
completed the supplemental questionnaires. Data from 467 hospitals were weighted number of hospitals operating 24-hour
to produce national annual estimates of ED characteristics. EDs decreased by 12% during the same
Results—There was an annual average of 4,500 EDs operating in the United time frame (1).Although most of the
States during 2003 and 2004. Over one-half of EDs saw less than 20,000 patients increase in visits can be explained by
annually, but 1 out of 10 had an annual visit volume of more than 50,000 patients. growth in the U.S. population, over
Although 16.1percent of hospitals expanded their ED physical space within the last one-third is accounted for by the growth
2 years, approximately one-third of others planned to do so within the next 2 years. in per capita use during the last 11 years
Most EDs used outside contracts to provide physicians (64.7percent). One-half of (2). Fewer EDs with increasing overall
EDs in metropolitan statistical areas (MSAs) had more than 5percent of their volume led to average increases in the
nursing positions vacant. Of all on-call specialists, the services of plastic and hand number of cases among operating EDs
surgeons were most frequently reported as somewhat or very difficult to obtain (up by 78% between 1995 and 2003)
(49.4percent).Approximately one-third of U.S. hospitals reported going on (Figure1) (3).
ambulance diversion sometime in the previous year.About 12percent of hospitals in Anumber of indicators have been
MSAs reported having spent between 5 and 19percent of their operating time in used to assess the capacity of EDs to
diversion status. Between 40 and 50percent of U.S. hospitals experienced crowded handle growth in demand, including the
conditions in the ED with almost two-thirds of metropolitan EDs experiencing time patients wait to receive services
crowding. (4), ED length of stay and treatment
time (which decreases the availability of
Keywords: crowding c emergency department c NHAMCS
Acknowledgments
ThisreportwaspreparedintheDivisionofHealthCareStatistics.KimberlyR.MiddletonintheAmbulatoryCareStatisticsBrancheditedthe
data.RobertoH.ValverdeintheTechnicalServicesBranchdevelopedtheanalyticalfiles.ThisreportwaseditedbyKlaudiaM.Cox,Officeof
InformationServices,InformationDesignandPublishingStaff;typesetbyAnnetteF.Holman,CoCHIS/NCHM/DivisionofCreativeServices;and
graphicswereproducedbyNOVAcontractor,KyungPark,ofCoCHIS/NCHM/DivisionofCreativeServices.
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Centers for Disease Control and Prevention
National Center for Health Statistics
2 Advance Data No. 376 + September 27, 2006
has an emergency medical condition, it
must provide appropriate stabilization
treatment or transfer (and hospitalization
if it is deemed necessary) (7). Hospitals
are held liable for the cost of care of
patients who are unable to pay their
bills. Increased use of the ED by
persons unable to pay their bills not
only influences patient volume, but
leads to increased uncompensated care.
Although hospitals do not keep records
of the amount of uncompensated care
for EMTALA-related care, theAmerican
HospitalAssociation has calculated that
the cost of uncompensated care was
$26.9 billion for all community
hospitals in 2004 (8).
Besides increased waiting times and
more patients leaving without being
Figure1.Volumeofannualvisitsperoperatingemergencydepartment:UnitedStates, seen, crowded EDs result in lengthened
1995–2003
EMS ambulance runs (9), ambulance
diversion (6,10), greater risk for poorer
space for other patients), the extent to emergency treatment, to treat or stabilize patient outcomes (11), and the lessened
which hospitals go on ‘‘diversion the patient for transfer to another ability of hospitals to respond to public
status’’(periods of time when facility. The Emergency Medical health emergencies including natural
ambulances are diverted to other Treatment andActive LaborAct disasters and mass casualty incidents. In
hospitals), and the percentage of patients (EMTALA) places two requirements on an effort to reduce crowding, ambulance
who leave the ED without being seen hospitals: first, a hospital must provide diversion practices resulted in the
(which may indicate patients’frustration an appropriate medical screening diversion of about 3percent of
at long wait times or delays in examination to anyone who comes to ambulance patients to more distant
treatment). These measures are the ED and requests examination or hospitals (12).Among the many other
important because they can be indicative treatment for a medical condition or for problems faced by EDs are lack of
of systemic hospital inpatient problems whom care is requested and second, if treatment space, on-call specialists, and
such as a shortage of inpatient beds and the hospital determines that the person language translation services. Much has
nursing staff (5).As inpatient discharges
and days of care declined through the
1980s and 1990s, many hospitals
Selectedemergencydepartmentstaffing,capacity,ambulancediversion,and
decreased bed availability to cut throughputindexesataglance
operating expenses and, as a result,
Not
occupancy rates increased, thereby Index Total1 Metropolitan2 metropolitan3
decreasing the hospitals’capacity to
handle an influx of patients from the ED Dailyvisitvolume. . . . . . . . . . . . . . . . . . 67.6 93.4 25.8
Standardtreatmentspaces. . . . . . . . . . . . 14.6 19.8 6.3
(6). Until now, there have been no
NumberofphysicianswithED4privileges. . . 13.3 17.5 6.4
national estimates of occupancy rates Dailyvisitspertreatmentspace . . . . . . . . . 4.6 4.9 4.1
and their relationship with ambulance Percentofnursingpositionsvacant. . . . . . . 5.3 6.1 3.9
diversion practices. Percentarrivingbyambulance. . . . . . . . . . 13.0 13.8 11.8
Averagewaitingtimeinminutes. . . . . . . . . 37.1 45.8 22.8
Understanding ED capacity is
Averagevisitdurationinminutes . . . . . . . . 159.7 181.6 124.2
important because hospitals may be Percentleftbeforeseen. . . . . . . . . . . . . . 1.4 1.8 0.7
unable to accept incoming patients when Percenttransferred. . . . . . . . . . . . . . . . . 3.0 2.1 4.5
Percentadmittedtohospital . . . . . . . . . . . 12.5 13.4 11.1
the volume of ED visits increases to a
Inpatientstaffedbedsize . . . . . . . . . . . . . 136.5 192.1 47.7
certain level. EDs experience pressure
Inpatientdailyoccupancyrate . . . . . . . . . . 60.3 66.4 50.6
when patients are boarded to await Annualhoursonambulancediversion . . . . . 146.0 242.7 0.5
admission while additional cases are
1Basedonresponsesfrom699emergencydepartments.
incoming. The crowding problem is 2Emergencydepartmentslocatedinmetropolitanstatisticalareas.
exacerbated by the fact that EDs are 3Emergencydepartmentslocatedinmicropolitanorruralareas.
4EDisemergencydepartment.
required by law to screen incoming
NOTE:MeansperemergencydepartmentintheUnitedStates,2003–04.
patients and if the patient needs
Advance Data No. 376 + September 27, 2006 3
been published on creative ways to known as the SMG Hospital Database. and 2004, a total of 1,060 hospitals
handle and measure ED crowding issues Using the 2003 data to update the were approached to determine their
(13–18), including increasing the sample allowed for the inclusion of eligibility.An additional 66 hospitals
efficiency of and removing barriers to hospitals that had opened or changed selected in 2003 were included without
patient flow. their eligibility status since the previous regard to sampled geographic areas to
Although the problem of ED sample was updated for 2001. increase the representation of rural and
crowding has received national attention The sample frame contains proprietary hospitals specifically for
(19), there have been no previous information about hospitals including making the facility-level estimates in
national surveys of how EDs operate in geographic region, metropolitan this report. Of all sample hospitals that
such a challenging environment. This statistical area status (metropolitan and operated 24-hour EDs, 83percent
report is the first to describe the not metropolitan, including rural areas), completed the supplemental
Nation’s EDs in terms of their staffing medical school affiliation, ownership, questionnaires (n=699 ED records (467
and capacity (including staff relative to and inpatient bed size.Although the unique hospitals, of which 235
treatment space available); the primary purpose of NHAMCS is to responded in both 2003 and 2004)) and
availability of specialized services (such estimate annual volume and provided the requisite amount of
as translation services and access to characteristics of medical encounters encounter records (76,842 visit records).
specialty physicians); the effect of occurring in EDs and OPDs, it also See the ‘‘Technical Notes’’for sample
demand and capacity on the ability to includes facility-level information. sizes and weighted response rates by
provide services (in the form of Atwo-stage probability sample hospital characteristics.
ambulance diversions, wait time, and design is used to select EDs in the No personally identifying
length of stay); and variability among NHAMCS. The design involves samples information is collected in NHAMCS.
EDs in areas that are metropolitan and of geographic primary sampling units The NHAMCS protocol was approved
not metropolitan. (PSUs) such as counties or groups of by the NCHS Research Ethics Review
See data highlights in the text box counties, representing the 50 states and Board and an exception to patient
on previous page. the District of Columbia and hospitals authorization for release of health
within PSUs. Hospitals are randomly information for the survey was granted
Methods assigned to 1 of 16 4-week rotating for compliance with the research
panels. In any given year, only 13 provisions of the Health Information
Sample and data collection panels are used. Hospitals are eligible Portability andAccountabilityAct
for ED facility questions if they report Privacy Rule. The U.S. Census Bureau
Aseries of special facility
having a 24-hour ED. was responsible for data collection and
supplements were added to the 2003–04
Afour-stage probability sample was processing of the supplements.
National HospitalAmbulatory Medical
used to collect information on ED visits.
Care Survey (NHAMCS) to assess the
The sample involves 112 geographic Survey instruments
structure and process characteristics of
PSUs, hospitals that have EDs or OPDs
hospitals related to their capacity to treat The supplements were self-report
within PSUs, emergency service areas
medical and surgical emergencies. instruments, which were left with
within EDs and clinics within OPDs,
NHAMCS is a national probability hospital staff at the time of induction
and patient visits within emergency
survey conducted by the Centers for into NHAMCS. The content of the
service areas and clinics. Hospital staff
Disease Control and Prevention’s supplements included information on
were asked to complete Patient Record
National Center for Health Statistics ED staffing, treatment and physical
forms for a systematic sample of 100
(NCHS). The target of the NHAMCS is space, language translation services,
visits that occur during a randomly
in-person visits made in the United inpatient occupancy, and ambulance
assigned 4-week reporting period. The
States to outpatient departments (OPDs) diversion. Completed questionnaires
2003 NHAMCS was conducted from
and EDs of nonfederal, short-stay were collected after the hospital’s
December 30, 2002, through December
hospitals (hospitals with an average assigned 4-week reporting period. The
28, 2003, and the 2004 NHAMCS was
length of stay of less than 30 days) or relevant content of the supplements is
conducted from December 29, 2003,
those whose specialty is general described below.
through December 26, 2004.
(medical or surgical) or children’s
To provide unbiased national annual + Staffing, Capacity, andAmbulance
general. The hospital sampling frame
estimates of EDs and their Diversion (SCAD)—Questions about
consisted of hospitals listed in the 1991
characteristics, a facility weight was treatment spaces, expansion of
Verispan Hospital Database (VHD)
constructed for each responding ED that physical space (2004 only),
updated using hospital data from
takes into account the selection of the credentials of ED physicians, contract
Verispan, L.L.C., specifically their
geographic area and hospital as well as staffing, nursing vacancies, difficulty
‘‘Healthcare Market Index, updated May
survey nonresponse. Detailed in providing on-call physician
15, 2003,’’and their ‘‘Hospital Market
information on NHAMCS, including its coverage for 19 specialties (2004
Profiling Solution, Second Quarter,
sample design and estimation strategies, only), availability of language
2003.’’These products were formerly
is reported elsewhere (20). During 2003
4 Advance Data No. 376 + September 27, 2006
translation services and list of summarized to provide a single measure national estimates averaged over 2003
languages provided (2004 only), other of each ED for analysis in this report. and 2004. There were a few supplement
nearby EDs, and regulations questions that were asked only during
prohibiting ambulance diversion (see Analysis 2004, for which the 2004 estimate is
http://www.cdc.gov/nhamcs/data/ supplied. Because estimates are based
For this report, aggregated estimates
NHAMCS-903.pdf for a copy of the on a sample rather than the entire
of each sampled hospital’s ED
form). universe, they are subject to sampling
utilization were created to describe how
+ Ambulance Diversion Log—Entries variability. Standard errors were
EDs vary with regard to important
made for each diversion period calculated using Taylor approximations
facility use characteristics. These
experienced during the 4-week in SUDAAN, which take into account
aggregated estimates come from the
reporting period including start and the complex sample design of
Patient Record form responses for each
end time, reason for diversion, and NHAMCS (21). Estimates whose
ED (see http://www.cdc.gov/nchs/data/
who authorized the diversion status standard error represents more than
ahcd/NHAMCS-100(ED)2004.pdf for a
(see http://www.cdc.gov/nhamcs/data/ 30percent of the estimate have an
copy of the form) and were merged to
NHAMCS-904.pdf for a copy of the asterisk (*) to indicate that they do not
each ED record that contained data on
log). meet the reliability standard set by
the facility from the induction interview,
+ Hospital Capacity Card—Numbers NCHS. Determination of statistical
supplements, and sample frame. Tables
and types of licensed and staffed significance was based at the 0.05 level.
in this report have estimates for all EDs
inpatient beds, daily entries of Additional information regarding
and separate estimates for EDs located
inpatient census, and number of open NHAMCS data collection, sampling or
in areas that are metropolitan and not
beds as of midnight for each day nonsampling errors, and estimation and
metropolitan. Metropolitan status is
during the reporting period (see tests of significance can be found in
based on the U.S. Census Bureau 2003
http://www.cdc.gov/nhamcs/data/ another publication (22).
definitions of MSAs. Hospitals located
NHAMCS-902.pdf for a copy of the Indexes of staffing, capacity,
in MSAs are considered metropolitan
card). ambulance diversion, and throughput for
hospitals, and the remaining are
+ Bioterrorism and Mass Casualty each ED were created from the above
considered not metropolitan hospitals
Preparedness (BT supplement)—Total data elements based on those suggested
and include those located in
number of hours on ambulance in the Solberg et al article (18). They
micropolitan and rural areas. Hospital
diversion during the previous year are shown in the text box below.
responses were weighted to produce
(see http://www.cdc.gov/nhamcs/data/
NHAMCS-905.pdf for a copy of the
form). For estimates from other items
Sourcesforselectedemergencydepartmentstaffingcapacity,ambulancediversion,
in this supplement, see http:// andthroughputindexes
www.cdc.gov/nchs/data/ad/ad364.pdf.
Index Source
Capacity and diversion measures
Dailyvisitvolume. . . . . . . . . . . . . . . . . Annualvisitvolumedividedby365.5
were created for each ED from the data
Standardtreatmentspaces. . . . . . . . . . . Responsefromstaffing,capacity,andambulance
collected on the above forms. For each diversion(SCAD)question
responding ED, information from the NumberofphysicianswithED1privileges. . ResponsefromSCADquestion
Dailyvisitspertreatmentspace . . . . . . . . Dailyvisitvolumedividedbynumberofstandard
diversion log was used to create an
treatmentspaces
average length of a diversion (median) Dailyvisitsperphysician . . . . . . . . . . . . Dailyvisitvolumedividedbynumberofphysicianswith
and summed to create total time on ED1privileges
Physiciansperspace. . . . . . . . . . . . . . . NumberofphysicianswithED1privilegesdividedby
diversion during the reporting period.
numberofstandardtreatmentspaces
The number of diversion entries was Percentageofnursingpositionsvacant . . . Responsefrom2004SCADquestion
also summed to provide a total number Percentagearrivingbyambulance . . . . . . Percentageofsampledvisitswithambulanceasmode
ofarrival
of diversion periods in each ED.
Averagewaitingtimeinminutes. . . . . . . . Meanwaitingtimefromsampledvisits
Percentages of time on diversion were Averagevisitdurationinminutes . . . . . . . Meanlengthofstayfromsampledvisits
calculated for each reason reported Percentageleftbeforeseen . . . . . . . . . . Percentageofsampledvisitswithleftasadisposition
Percentagetransferred. . . . . . . . . . . . . . Percentageofsampledvisitswithtransferasa
(multiple entries allowed per diversion
disposition
period). The daily inpatient census Percentageadmittedtohospital. . . . . . . . Percentageofsampledvisitswithadmitasa
information for each of the 28 days and disposition
Inpatientstaffedbedsize . . . . . . . . . . . . Numberofstaffedbedsfromthesampleframe
the number of staffed beds reported on
Inpatientdailyoccupancyrate . . . . . . . . . Meanpercentageofstaffedbedsoccupiedatmidnight
the Hospital Capacity Card were used to duringthe28-dayreportingperiodfromtheHospital
CapacityCard
calculate an average daily occupancy
Annualhoursondiversion. . . . . . . . . . . . Responsefromthebioterrorismquestionon
rate (mean) for each ED.Although the ambulancediversionhours
variation among days in occupancy rates
1EDisemergencydepartment.
and numbers of diversion periods is of
interest, these variables were
Advance Data No. 376 + September 27, 2006 5
Crowding in the ED is a result of
demand exceeding capacity.Although
crowding is often measured as an
opinion of ED staff or recently
measured as full waiting rooms (23, 24),
NHAMCS did not collect these data
elements. To estimate the number of
hospitals experiencing ED crowding,
responses to the SCAD and BT
supplements and estimates of throughput
from the NHAMCS visit data for each
hospital were used. Therefore, in this
report, the measure of whether the ED
experienced crowded conditions was
obtained using the following criteria:
having any ambulance diversion hours
reported, having a mean waiting time
for urgent cases greater than 60 minutes,
or having the percentage of cases left
without being seen greater than or equal
to 3percent. In a raw sample, 428 ED
records met the criteria for crowding
and 149 did not.Anational estimate of
the percentage of hospitals experiencing
crowding is presented, as well as those
indexes with significant differences Figure2.Percentageofemergencydepartmentsthathaverecentlyexpandedorplanto
(p<.05) between EDs experiencing expandphysicalspace,byselectedcharacteristics:UnitedStates,2004
crowded conditions and those that did
not.
compared with 17.1percent of diversion hours reported and larger
metropolitan hospitals. average visit durations.
Results
Treatment spaces Staffing
There was an average of 4,500 EDs
operating in the United States during EDs in metropolitan areas reported Most EDs employed physicians
2003 and 2004. Two-thirds were located more standard and auxiliary treatment using outside contracts (64.7percent).
in states within the Midwest and South; spaces than those not in metropolitan Presence of emergency medicine
4 out of 10 were located in areas that areas (Table2).Auxiliary treatment specialists (either through board
are not metropolitan (Table1). Most spaces may include chairs or hallway certification or emergency medicine
EDs were operated by voluntary, stretchers. Due to the higher volume residency programs) varied greatly
nonprofit hospitals (65.2percent), and found in metropolitan areas, across hospitals (Table3). In many EDs
many were located in hospitals with metropolitan EDs were more likely to (38.7percent), some or all ED
fewer than 100 beds (57.2percent). have increased both the number of physicians had responsibilities elsewhere
Public hospitals accounted for one- treatment spaces and their physical in the hospital, such as providing
quarter of all EDs. Over one-half of space within the last 2 years.Although inpatient care or administrative
EDs saw fewer than 20,000 cases 16.1percent of all hospitals expanded functions. Physicians in hospitals in
annually, but 1 out of 10 EDs had an their ED physical space within the last 2 areas that were not metropolitan were
annual visit volume of more than 50,000 years, approximately one-third of others more apt to have non-ED
cases. EDs in metropolitan areas tended plan to do so within the next 2 years. responsibilities than those in
to have a much larger visit volume than About 43.2percent of all EDs recently metropolitan hospitals. EDs in
their counterparts in areas that are not expanded or plan to do so, but metropolitan areas were more likely to
metropolitan. The average daily expansion varied by most ED have nursing vacancies.Although
inpatient occupancy rate in metropolitan characteristics (Figure2). EDs more 34.7percent of metropolitan EDs had
hospitals was also larger than in likely to choose expansion included 5% or more of their nursing positions
hospitals in areas that were not those with higher volume; those vacant, only 18.3percent of EDs in
metropolitan. One-half of hospitals not classified as proprietary, voluntary, or areas that were not metropolitan had 5%
in metropolitan areas reported nonprofit; those affiliated with medical or more vacant nursing positions
occupancy rates under 50percent schools; and those with any ambulance (calculated from Table3).About
6 Advance Data No. 376 + September 27, 2006
on ambulance diversion status sometime
in the previous year, whereas
51.4percent reported no diversion hours.
Information on the number of hours on
diversion was missing for 14.2percent
of EDs. Metropolitan hospitals were
more likely to have diversion hours
reported (50.1percent) compared with
hospitals not in metropolitan areas
(9.2percent).About 12percent of
metropolitan hospitals reported having
spent 5–19% of their operating time in
diversion status, with about 2.7percent
spending 20% or more of their time on
diversion (Table4).Although the
duration of ambulance diversion periods
varies widely, the most frequently
reported duration ranged between 3 and
4 hours. Lack of inpatient beds and ED
crowding were frequent reasons for
going on diversion. Staffing shortages
and equipment failure were cited less
frequently (Figure4). Diversion periods
were most frequently ordered by nursing
Figure3.Percentageofemergencydepartmentsindicatingdifficultyinprovidingon-call
staff or the hospital administrator
physiciansbyphysicianspecialty:UnitedStates,2004
(Figure5). Percentage of time on
diversion is positively related to
occupancy rates and bed sizes of
hospitals. Figure6 plots the centroid for
EDs on occupancy and bed size by
percentage of time on diversion (none,
1–4%, 5–9%, 10–19%, and 20% or
more). For example, EDs with no
diversion hours reported had the
smallest mean bed size (138) and
smallest mean occupancy rate (60%),
and EDs reporting 20% or more of their
time on diversion had the largest mean
bed size (311) and largest mean
occupancy rate (81%).
Triage levels
EDs often use nursing triage to
identify the most urgent patients
(Table5). Most hospitals used a 3- or
Figure4.Meanpercentageofdiversionhoursbyreasonsfordiversion:UnitedStates,
4-level triage system (63.6percent), and
2003–04
about one-quarter used a 5-level system.
three-quarters of EDs that were not in or very difficult to obtain (Figure3). Language translation services
metropolitan areas reported that less The services of radiologists and
EDs reported providing a wide
than 5% of nursing positions were anesthesiologists were fairly easy to
range of translation services.Although
vacant compared with one-half of obtain.
Spanish was the most frequent language
metropolitan EDs. Difficulties in
provided (77.5percent of EDs), Russian,
obtaining services of on-call specialists Ambulance diversion
French, Chinese, and Vietnamese were
were reported in many EDs, with plastic
Approximately one-third of U.S. each reported as available in 10–14
surgeons and hand surgeons more
hospitals (34.4percent) reported going percent of metropolitan EDs.
frequently being reported as somewhat
Advance Data No. 376 + September 27, 2006 7
patients arriving via ambulance. One in
five EDs had less than 20% triaged as
emergent or urgent, whereas
38.1percent of EDs had 65% or more
of their cases so triaged. ED caseload
acuity did not vary by metropolitan
status. However, the provision of
diagnostic or therapeutic services did
vary, with metropolitan EDs providing
greater numbers of services per 100
cases (Table6). For example, only
19.4percent of metropolitan EDs
provided an average of less than 40
therapeutic services (e.g., intravenous
fluids, wound care) per 100 visits
compared with 41.5percent of EDs not
in metropolitan areas.About
28.6percent of metropolitan EDs
provided an average of 70 or more
Figure5.Meanpercentageofdiversionhoursbywhoorderedthediversion: therapeutic services per 100 visits
UnitedStates,2003–04
compared with 12.9percent of EDs not
in metropolitan areas.About one-half of
EDs employed the services of physician
assistants and nurse practitioners, with
18.5percent using their services in 20%
or more of their cases.
On average, 2percent of cases were
transferred to another facility. However,
18.5percent of EDs transferred an
average of 10% or more of their cases
to other hospitals. Overall, only
1.7percent of cases left without being
seen, although 7.2percent of EDs had
5% or more of their patients leave
without seeing a physician.
Waiting times in metropolitan areas
were longer than in areas that were not
metropolitan. One-fifth of patients in
metropolitan EDs waited over an hour
Figure6.Percentageoftimeonambulancediversionasafunctionofhospitalbedsize
to see a physician, whereas 31.7percent
andoccupancyrateinmetropolitanemergencydepartments:UnitedStates,2003–04
of patients in areas that were not
metropolitan were seen within 15
Emergency department reported that 25% or more of their cases
minutes.About 12.8percent of
utilization were uninsured (Table6). Figure7
metropolitan EDs had average waiting
shows the distribution of EDs on the
EDs varied widely in terms of their times greater than 60 minutes for their
relative caseloads for expected payment
profile of patient and payment urgent cases, which are defined during
sources. For example, private insurance
characteristics, diagnostic and treatment triage as cases that should be seen
accounts for about 33% of all ED visits,
services, and case disposition (Table6). between 15 and 60 minutes after arrival
and uninsured cases make up about 15%
Two-thirds of EDs not in metropolitan (Table6). Overall, treatment times
of all ED visits. These percentages
areas saw fewer than 30 cases each day. tended to be longer in metropolitan
varied considerably among EDs.
In contrast, two-thirds of metropolitan areas than in areas that were not
ED caseloads also varied by patient
EDs cared for 50–200 cases each day. metropolitan. For example, about
acuity as measured by cases arriving by
Children represented 10–30% of the ED one-half of patients in areas that were
ambulance and cases triaged as
caseload, and seniors represented 5–25% not metropolitan spent less than 90
emergent or urgent.About one-third of
of the caseload. One in 10 EDs reported minutes in the treatment area, whereas
hospitals had less than 10% of their
that 50% or more of their cases had in metropolitan areas only one in five
patients arriving via ambulance, and
Medicaid, and 18.6percent of EDs patients had treatments that lasted less
13.8percent had 30% or more of their
8 Advance Data No. 376 + September 27, 2006
and treatment times contributed to total
visit duration being longest in EDs that
go on diversion 20% or more of the
time. Metropolitan visits lasted 2–3
times longer than nonmetropolitan visits,
on average.
Indexes of staffing, capacity,
and throughput
Table7 presents selected indexes of
ED functioning using measures from
NHAMCS. The indexes are mean
estimates for all EDs combined and
separately for those in metropolitan
areas and areas that were not
metropolitan. The 25th, 50th, and 75th
percentiles are also presented to show
the variation across EDs. Significant
differences between urban and rural
areas were found for all indexes with
Figure7.Boxplotsofemergencydepartmentsoncaseloadpercentagesforexpected
the exception of visits per space, visits
sourcesofpayment:UnitedStates,2003–04
per physician, physicians per space,
percentage arriving by ambulance, and
percentage admitted to hospital. For EDs
that had any diversion, the average
number of hours on diversion for the
year was 363.9; among metropolitan
EDs, the average number of hours on
diversion was 403.9 (Table7). For
metropolitan EDs, 25percent reported
being on diversion for more than 524.4
hours during the previous year.
Estimates of ED crowding
Ambulance diversion cannot be
used as the sole criteria for ED
crowding because about 8percent of
hospitals reported that there were laws
prohibiting that practice in their
location. Using the criteria of any
ambulance diversion hours, average
waiting time greater or equal to 60
minutes for urgent cases, or percentage
of visits where the patient left before
being seen greater than or equal to
3percent, approximately 44.9percent
(95% confidence interval, 39.8 to 50.0)
of EDs experienced crowding some time
during 2003 and 2004.Approximately
63.7percent of metropolitan EDs
experienced crowding compared with
Figure8.Averagetotalvisitdurationparsedbywaitingandtreatmenttimesin 14.4percent of EDs that were not
metropolitanareasbyemergencydepartmentcharacteristics:UnitedStates,2003–04
metropolitan. Because EDs experiencing
crowding tend to be larger in annual ED
than 90 minutes. The total ED visit the total visit duration parsed by waiting
visit volume, this corresponds to
duration is the sum of the waiting time and treatment times according to
62.6percent of all emergency visits
and the treatment time. Figure8 displays selected ED characteristics. Both waiting
being made to hospitals that experienced
Advance Data No. 376 + September 27, 2006 9
ED crowding.Additionally, crowding
was more common among EDs with
larger inpatient bed sizes and those
associated with medical schools
(Figure9).
When examining differences in the
staffing, capacity, and throughput
indexes for EDs located in metropolitan
areas, EDs experiencing crowding were
significantly higher than those not
experiencing crowding for about
one-half of those measures (Figure10).
The percentage of cases left before
being seen in crowded EDs (2.1%) was
four times as high as the percentage in
uncrowded EDs (0.4%). The percentage
of nursing positions vacant in crowded
EDs (7.7%) was twice that of
uncrowded EDs (3.9%).Average waiting
time was 50% longer in crowded EDs
(51.8 minutes) compared with
uncrowded EDs (35.4 minutes).
Discussion
This report shows how U.S.
nonfederal, general, and short-stay
hospitals vary with respect to structure,
process, and patient attributes in
providing emergency medical care.
National estimates of the steps hospitals
take to provide such care are described
separately for hospitals located in
Figure9.Percentageofemergencydepartmentsthatexperiencedcrowdingbyselected
metropolitan areas and in areas that
hospitalcharacteristics:UnitedStates,2003–04
were not metropolitan. The fundamental
differences in the size of metropolitan
hospitals, both in terms of bed size and
ED visit volume, affect many of the
observed differences in staffing patterns,
ED crowding, and duration of visits. In
effect, the problems facing urban EDs
are very different than those facing rural
EDs. In areas that were not
metropolitan, most EDs are the only one
available for patients residing in the
catchment area. There are no ‘‘nearby’’
choices for an emergency visit, whereas
most metropolitan EDs have several
other EDs available within a 20-minute
ambulance ride or a 5-mile radius. ED
patient profiles also vary by
metropolitan status. EDs that are not in
metropolitan areas were more likely to
have a higher proportion of Medicare
patients and to transfer patients.
Figure10.Ratioofindexeswithsignificantdifferencesbetweencrowdedanduncrowded One area of distinction between
emergencydepartmentsinmetropolitanareas hospitals that are in metropolitan or not
10 Advance Data No. 376 + September 27, 2006
metropolitan areas is the issue of labor-intensive patients, resulting in system were predominantly in
crowding. NHAMCS data provide decreased capacity (25). The NHAMCS metropolitan areas.
information on key measures of ED results showed that metropolitan status This survey found that multiple
crowding. Some of the indexes was not related to expanding physical language services were available more
developed by an expert panel (18) space. frequently in metropolitan EDs. Medical
covering several domains of ED This report shows that ED treatment errors may result from patient-provider
functioning (e.g., patient demand, ED spaces and staffing levels vary across communication problems due to
capacity, patient complexity, and ED metropolitan and not metropolitan areas. language barriers. Limited English
efficiency) were used to describe EDs Most EDs that are not in metropolitan proficiency can lead to increased use of
experiencing crowding. Using the areas have fewer than 10 standard medical resources in children (30) and
definition of crowding in this report, 40 treatment spaces, where metropolitan serious medical events during pediatric
to 50percent of U.S. EDs experienced EDs typically have 10 to 50 spaces. hospitalizations (31). NHAMCS data
crowding at some point in 2003 and Providing nursing staff to cover all the showed that over 90percent of EDs
2004.Among EDs located in spaces in metropolitan areas is another reported providing language translation
metropolitan areas, the percentage matter. NHAMCS found that one-quarter services, with one-third offering 30 or
increased to 64percent. Indexes of ED of metropolitan EDs had 5–19percent of more different languages.
functioning related to demand, capacity, their nursing positions vacant. In Visit and patient profile patterns
and throughput found that one-half of addition to nursing shortages in the ED, differed among hospitals indicating wide
those studied were related to crowded there is the problem of high turnover variation in reimbursement and
conditions in metropolitan EDs. leading to a high proportion of new, treatment practices. Over one-quarter of
Surprisingly, indexes of staffing were inexperienced emergency nurses. hospitals had 30% or more of their
not related to crowding with the Sometimes nurses unfamiliar with the visits made by Medicaid recipients, and
exception of the percentage of nursing ED are sent to work from other areas of about one-fifth had 25% or more of
positions vacant. the hospital, which can contribute to their visits made by uninsured persons.
This report showed that periods of reduced efficiency in the delivery of Such hospitals treat a larger proportion
ambulance diversion occurred in care (7). of cases from safety-net populations and
one-half of EDs located in metropolitan On-call physician specialists provide are at risk of higher rates of
areas.Ambulance diversion is an effect specialized care for patients beyond the uncompensated care. Most of these high
of ED crowding and some of its expertise of the emergency physician safety-net hospitals do not receive
consequences are increased transit times and usually have no guarantee of sufficient Medicaid Disproportionate
and the potential for poor clinical payment for the services they provide. Share Program funds to offset their
outcomes (5). In addition, a study From a specialist’s business perspective, financial losses (32). Collected charges
conducted in LosAngeles found that being on-call may result in time spent for self-pay patients are as low as 1%
diversion hours at one ED were with little generation of income (26). for the hospital to under 20% for the
interrelated with the diversion hours of NHAMCS data showed that on-call physician (33,34). Office-based
the nearest ED so that when one ED services provided by plastic and hand physicians are also at risk for under
went on diversion, others nearby soon surgeons were the most difficult to payment when they provide EMTALA-
followed. In addition to crowding in the obtain compared with other specialties. related care in hospitals. In 2003–04,
ED, a leading reason for ambulance ACalifornia survey of emergency 22.8percent of office-based physicians
diversion is insufficient appropriate medicine physicians found that five of reported that they spent an average of
inpatient beds to place critically ill or the seven specialities in which the 10.6 hours providing EMTALA-related
injured patients.As with the 2002 greatest proportion of EDs reported care during their last full week of work.
GovernmentAccountability Office study trouble with specialty response were (35)
of metropolitan EDs (6), NHAMCS surgical (27). Hospitals also vary with respect to
found that diversion was positively Triage systems are known to vary numbers of pediatric cases seen in the
related to hospital inpatient occupancy from hospital to hospital. However, they ED.Aseparate study using
rates. The average occupancy rate for all share the same goal of prioritizing supplemental data from the 2002–03
metropolitan hospitals with no patients for treatment. This prioritization NHAMCS found that hospitals with few
diversions was 60%, whereas it was is relevant to patient safety, especially pediatric ED cases are least prepared for
81% for hospitals that spent as much as when ED crowding delays evaluation. handling the stabilization of severe
20% of their time on diversion. Although research found that the pediatric emergencies with regard to
Increasing demand on EDs that are reliability and validity of the Emergency small-sized equipment, such as needles,
still open has caused almost one-half of Severity Index, a 5-level triage system, endotracheal tubes, and access to
all EDs to expand their physical space. were better than in a 3-level system emergency medicine specialists,
ACalifornia study found that although (28,29), NHAMCS findings showed that especially those specializing in pediatric
the number of beds per population about one-quarter of U.S. EDs used the emergencies (36). The NHAMCS data
remained stable during the 1990s, the former, and those that used the 5-level in this report found that one-fifth of
beds were being occupied by more EDs transferred as much as 10% or