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