The effect of emergency department crowding on clinically oriented outcomes

A regional survey to determine factors influencing patient choices in selecting a particular emergency department for care

OBJECTIVES

Increases in regional emergency department (ED) efficiencies might be obtained by shifting patients to less crowded EDs. The authors sought to determine factors associated with a patient's decision to choose a specific regional ED. Based on prior focus group discussions with volunteers, the hypothesis was that distance to a specific ED and perceived ED wait times would be important.

METHODS

A cross-sectional survey was developed using qualitative focus group methodology. The resulting survey was composed of 17 questions relating to patient decisions in choosing a specific ED and was administered in each of six EDs in a single urban Canadian health region at all hours of the day. Ambulatory patients with a Canadian Triage and Acuity Scale (CTAS) level 3 to 5 and aged ≥19 years were surveyed. The primary outcome was the proportion of patients whose main motivation for attending a specific ED was either distance traveled to reach the ED or perceived ED waiting time. Multivariable logistic regression was performed to assess factors influencing both of these reasons.

RESULTS

A total of 757 patients were approached and 634 surveys (83.8%) were completed. Distance from the ED (named by 44.0% of respondents as their primary reason) and perceived ED wait times (9.3%) were the main motivations for patients to attend a specific ED. Multivariable analysis of factors associated with choosing distance revealed that ED distance < 10 km (adjusted odds ratio [OR] = 2.20, 95% confidence interval [CI] = 1.45 to 3.33; p = 0.001) and age ≥ 60 years (adjusted OR = 1.58, 95% CI = 1.12 to 2.26; p = 0.04) were significant in choosing a particular ED. Multivariable analysis of factors influencing wait times demonstrated that having a painful complaint (adjusted OR = 1.42, 95% CI = 1.05 to 1.98; p = 0.047) and age < 60 years (OR = 1.47, 95% CI = 1.02 to 2.14; p = 0.049) were significant in choosing a particular ED.

CONCLUSIONS

In a multicenter survey of patients from an urban health region, distance to a specific ED and perceived ED wait times were the most important reasons for choosing that ED. Younger patients and those with painful conditions appear to place greater priority on wait times.

Risk factors for unplanned transfer to intensive care within 24 hours of admission from the emergency department in an integrated healthcare system

BACKGROUND

Emergency department (ED) ward admissions subsequently transferred to the intensive care unit (ICU) within 24 hours have higher mortality than direct ICU admissions.

DESIGN, SETTING, PATIENTS

Describe risk factors for unplanned ICU transfer within 24 hours of ward arrival from the ED.

METHODS

Evaluation of 178,315 ED non-ICU admissions to 13 US community hospitals. We tabulated the outcome of unplanned ICU transfer by patient characteristics and hospital volume. We present factors associated with unplanned ICU transfer after adjusting for patient and hospital differences in a hierarchical logistic regression.

RESULTS

There were 4,252 (2.4%) non-ICU admissions transferred to the ICU within 24 hours. Admitting diagnoses most associated with unplanned transfer, listed by descending prevalence were: pneumonia (odds ratio [OR] 1.5; 95% confidence interval [CI] 1.2-1.9), myocardial infarction (MI) (OR 1.5; 95% CI 1.2-2.0), chronic obstructive pulmonary disease (COPD) (OR 1.4; 95% CI 1.1-1.9), sepsis (OR 2.5; 95% CI 1.9-3.3), and catastrophic conditions (OR 2.3; 95% CI 1.7-3.0). Other significant predictors included: male sex, Comorbidity Points Score >145, Laboratory Acute Physiology Score ≥7, arriving on the ward between 11 PM and 7 AM. Decreased risk was found with admission to monitored transitional care units (OR 0.83; 95% CI 0.77-0.90) and to higher volume hospitals (OR 0.94 per 1,000 additional annual ED inpatient admissions; 95% CI 0.91-0.98).

CONCLUSIONS

ED patients admitted with respiratory conditions, MI, or sepsis are at modestly increased risk for unplanned ICU transfer and may benefit from better triage from the ED, earlier intervention, or closer monitoring to prevent acute decompensation. More research is needed to determine how intermediate care units, hospital volume, time of day, and sex affect unplanned ICU transfer. Journal of Hospital Medicine 2013. © 2012 Society of Hospital Medicine.

Effect of emergency department crowding on outcomes of admitted patients

STUDY OBJECTIVE

Emergency department (ED) crowding is a prevalent health delivery problem and may adversely affect the outcomes of patients requiring admission. We assess the association of ED crowding with subsequent outcomes in a general population of hospitalized patients.

METHODS

We performed a retrospective cohort analysis of patients admitted in 2007 through the EDs of nonfederal, acute care hospitals in California. The primary outcome was inpatient mortality. Secondary outcomes included hospital length of stay and costs. ED crowding was established by the proxy measure of ambulance diversion hours on the day of admission. To control for hospital-level confounders of ambulance diversion, we defined periods of high ED crowding as those days within the top quartile of diversion hours for a specific facility. Hierarchic regression models controlled for demographics, time variables, patient comorbidities, primary diagnosis, and hospital fixed effects. We used bootstrap sampling to estimate excess outcomes attributable to ED crowding.

RESULTS

We studied 995,379 ED visits resulting in admission to 187 hospitals. Patients who were admitted on days with high ED crowding experienced 5% greater odds of inpatient death (95% confidence interval [CI] 2% to 8%), 0.8% longer hospital length of stay (95% CI 0.5% to 1%), and 1% increased costs per admission (95% CI 0.7% to 2%). Excess outcomes attributable to periods of high ED crowding included 300 inpatient deaths (95% CI 200 to 500 inpatient deaths), 6,200 hospital days (95% CI 2,800 to 8,900 hospital days), and $17 million (95% CI $11 to $23 million) in costs.

CONCLUSION

Periods of high ED crowding were associated with increased inpatient mortality and modest increases in length of stay and costs for admitted patients.

Occult psychosocial impairment in a pediatric emergency department population

OBJECTIVES

We compared the degree of psychosocial impairment in patients seen in the emergency department (ED) for acute complaints with that of patients presenting with chronic complaints using the Youth Pediatric Symptom Checklist (PSC-Y). Our hypothesis was that patients with multiple visits for chronic complaints (>3 health care visits for the chief complaint during the previous 12 months) would be more likely than patients with acute complaints to test positive for psychosocial issues.

METHODS

The PSC-Y was administered to patients aged 8 to 18 years presenting to a pediatric ED for nonpsychiatric complaints. We compared proportions of patients testing positive for psychosocial impairment on the PSC-Y or any of its subscales.

RESULTS

In the 442 patients enrolled, 25% endorsed chronic symptoms. There was a significant difference in the proportion of patients scoring positive for psychosocial impairment between the acute and chronic group (13.8% vs 18.1%, P = 0.002) as well as in the proportion of patients testing positive for attentional issues (6.4% vs 13.9%, P = 0.02). Each subscale was analyzed independently, and there were no statistically significant intergroup differences in internalizing symptoms (anxiety, depression) or externalizing symptoms (conduct issues).

CONCLUSIONS

Patients with recurrent presentations for the same complaint had significantly higher rates of overall psychosocial impairment. Regardless of complaint acuity, impairment rates were notable, with 20% of patients reporting internalizing symptoms, such as anxiety and depression. Psychosocial issues should be considered in all pediatric ED patients but particularly those with greater than 3 health care visits for the same presenting complaint.

Effect of a physician assistant as triage liaison provider on patient throughput in an academic emergency department

OBJECTIVES

Overcapacity issues plague emergency departments (EDs). Studies suggest that triage liaison providers (TLPs) may shorten patient length of stay (LOS) and reduce the proportion of patients who leave without being seen (LWBS), but these results are not universal. Previous studies used physicians as TLPs. We evaluated whether a physician assistant (PA), acting as a TLP, would shorten LOS and decrease LWBS rates.

METHODS

The authors used an observational cohort controlled before-and-after study design with predefined outcome measures, comparing 8 pilot days to 8 control days. The TLP evaluated all Emergency Severity Index (ESI) level 3, 4, and 5 patients, excluding pediatric and behavioral health patients.

RESULTS

A total of 353 patients were included on pilot days and 371 on control days. LOS was shorter on pilot days than control days (median [interquartile range {IQR}] = 229 [168 to 303] minutes vs. 270 [187 to 372] minutes, p < 0.001). Waiting room times were similar between pilot and control days (median [IQR] = 69 [20 to 119] minutes vs. 70 [19 to 137] minutes, p = 0.408), but treatment room times were shorter (median [IQR] = 151 [92 to 223] minutes vs. 187 [110 to 254] minutes, p < 0.001). Finally, a lower proportion of patients LWBS on pilot days (1.4% vs. 9.7%, p < 0.001).

CONCLUSIONS

The addition of a PA as a TLP was associated with a 41-minute decrease in median total LOS and a lower proportion of patients who LWBS. The decrease in total LOS is likely attributable to the addition of the TLP, with patients having shorter duration in treatment rooms on pilot days compared to control days.

Physician in triage improves emergency department patient throughput

To determine if a physician in triage (PIT) improves Emergency Department (ED) patient flow in a community teaching hospital. This is an interventional study comparing patient flow parameters for the 3-month periods before and after implementation of a PIT model. During the interventional time an additional attending physician was assigned to triage from 1 p.m. to 9 p.m. daily. Outcome measures were median time to attending physician evaluation, median length of stay (LOS), number of patients who left without being seen (LWBS), and total time and number of days on ambulance diversion. Non-normally distributed values were compared with the Wilcoxon rank sum test. Proportions were compared with Chi-square test. Outcome measures were available for 17,631 patients, of whom 8,620 were seen before the initiation of PIT, and 9,011 were seen after PIT was implemented. For all patients, the median time from registration to attending physician evaluation was reduced by 36 min (1:41 to 1:05, p < 0.01) while the median LOS for all patients was reduced by 12 min (3:51 to 3:39, p < 0.01) after the intervention. Both the number of days on diversion (24 vs. 9 days) and total time on diversion (68 h 25 min vs. 26 h 7 min) were decreased, p < 0.01. Finally, there was a slight reduction in the number of patients who LWBS from 1.5 to 1.3 %, but this was not statistically significant (p = 0.36). Patient flow parameters in a community teaching hospital were modestly improved as a result of PIT implementation.

Emergency department inter-hospital transfer for post-cardiac arrest care: initial experience with implementation of a regional cardiac resuscitation center in the United States

OBJECTIVE

The American Heart Association recently recommended regional cardiac resuscitation centers (CRCs) for post-resuscitation care following out-of-hospital cardiac arrest (OHCA). Our objective was to describe initial experience with CRC implementation.

METHODS

Prospective observational study of consecutive post-resuscitation patients transferred from community Emergency Departments (EDs) to a CRC over 9 months. Transfer criteria were: OHCA, return of spontaneous circulation (ROSC), and comatose after ROSC. Incoming patients were received and stabilized in the ED of the CRC where advanced therapeutic hypothermia (TH) modalities were applied. Standardized post-resuscitation care included: ED evaluation for cardiac catheterization, TH (33-34 °C) for 24h, 24h/day critical care physician support, and evidence-based neurological prognostication. Prospective data collection utilized the Utstein template. The primary outcome was survival to hospital discharge with good neurological function [Cerebral Performance Category 1 or 2].

RESULTS

Twenty-seven patients transferred from 11 different hospitals were included. The majority (21/27 [78%]) had arrest characteristics suggesting poor prognosis for survival (i.e. asystole/pulseless electrical activity initial rhythm, absence of bystander cardiopulmonary resuscitation, or an unwitnessed cardiac arrest). The median (IQR) time from transfer initiation to reaching TH target temperature was 7(5-13)h. Ten (37%) patients survived to hospital discharge, and of these 9/10 (90% of survivors, 33% of all patients) had good neurological function.

CONCLUSIONS

Despite a high proportion of patients with cardiac arrest characteristics suggesting poor prognosis for survival, we found that one-third of CRC transfers survived with good neurological function. Further research to determine if regional CRCs improve outcomes after cardiac arrest is warranted.

Day of surgery admission for the elective surgical in-patient: successful implementation of the Elective Surgery Programme

BACKGROUND AND AIMS

The aim of this prospective cross-sectional study was to determine the impact of (1) ring fencing in-patient general surgical beds and (2) introducing a pre-operative assessment clinic (PAC) on the day of surgery admission (DOSA) rate in a single Irish institution. The secondary aim was to analyse the impact of an increased rate of DOSA on cost efficiency and patient satisfaction.

METHODS

An 18-month period was examined following ring-fencing of elective and emergency surgical beds. A PAC was established during the study period. Prospectively collected data pertaining to all surgical admissions were retrieved using patient administration system software (Powerterm Pro, Eircom Software) and a database of performance information from Irish Public Health Services (HealthStat).

RESULTS

Ring-fencing and PAC establishment was associated with a significant increase in the overall DOSA rate from 56 to 85%, surpassing the national target rate of DOSA (75%). Data relating specifically to general surgery admissions mirrored this increase in DOSA rate from a median of 5 patients per month, before the advent of ring-fencing and PAC, to 42 patients per month (p < 0.0387). 100 patient surveys demonstrated high levels of satisfaction with DOSA, with a preference compared to admission one night pre-operatively. Cost analysis demonstrated overall savings of 340,370 Euro from this change in practice.

CONCLUSION

The present study supports the practice of DOSA through the introduction of ring-fenced surgical beds and PAC. This has been shown to improve hospital resource utilisation and streamline surgical service provision in these economically challenging times.

Physician-led team triage based on lean principles may be superior for efficiency and quality? A comparison of three emergency departments with different triage models

Background

The management of emergency departments (EDs) principally involves maintaining effective patient flow and care. Different triage models are used today to achieve these two goals. The aim of this study was to compare the performance of different triage models used in three Swedish EDs. Using efficiency and quality indicators, we compared the following triage models: physician-led team triage, nurse first/emergency physician second, and nurse first/junior physician second.

Methods

All data of patients arriving at the three EDs between 08:00- and 21:00 throughout 2008 were collected and merged into a database. The following efficiency indicators were measured: length of stay (LOS) including time to physician, time from physician to discharge, and 4-hour turnover rate. The following quality indicators were measured: rate of patients left before treatment was completed, unscheduled return within 24 and 72 hours, and mortality rate within 7 and 30 days.

Results

Data from 147,579 patients were analysed. The median length of stay was 158 minutes for physician-led team triage, compared with 243 and 197 minutes for nurse/emergency physician and nurse/junior physician triage, respectively (p < 0.001). The rate of patients left before treatment was completed was 3.1% for physician-led team triage, 5.3% for nurse/emergency physician, and 9.6% for nurse/junior physician triage (p < 0.001). Further, the rates of unscheduled return within 24 hours were significantly lower for physician-led team triage, 1.0%, compared with 2.1%, and 2.5% for nurse/emergency physician, and nurse/junior physician, respectively (p < 0.001). The mortality rate within 7 days was 0.8% for physician-led team triage and 1.0% for the two other triage models (p < 0.001).

Conclusions

Physician-led team triage seemed advantageous, both expressed as efficiency and quality indicators, compared with the two other models.

Predictive variables of an emergency department quality and performance indicator: a 1-year prospective, observational, cohort study evaluating hospital and emergency census variables and emergency department time interval measurements

OBJECTIVE

Emergency department (ED) crowding impacts negatively on quality of care. The aim was to determine the association between ED quality and input, throughput and output-associated variables.

METHODS

This 1-year, prospective, observational, cohort study determined the daily percentage of patients leaving the ED in <4 h (ED quality and performance indicator; EDQPI). According to the median EDQPI two groups were defined: best-days and bad-days. Hospital and ED variables and time interval metrics were evaluated as predictors.

RESULTS

Data were obtained for 67 307 patients over 364 days. Differences were observed between the two groups in unadjusted analysis: number of daily visits, number of patients as a function of final disposition, number boarding in the ED, and time interval metrics including wait time to triage nurse and ED provider, time from ED admission to decision, time from decision to departure and length of stay (LOS) as a function of final disposition. Five variables remained significant predictors for bad-days in multivariate analysis: wait time to triage nurse (OR 2.36; 95% CI 1.36 to 4.11; p=0.002), wait time to ED provider (OR 1.93; 95% CI 1.05 to 3.54; p=0.03), number of patients admitted to hospital (OR 1.86; 95% CI 1.09 to 3.19; p=0.02), LOS of non-admitted patients (OR 9.5; 95% CI 5.17 to 17.48; p<0.000001) and LOS of patients admitted to hospital (OR 2.46; 95% CI 1.44 to 4.2; p=0.0009).

CONCLUSIONS

Throughput is the major determinant of EDQPI, notably time interval reflecting the work dynamics of medical and nursing teams and the efficacy of fast-track routes for low-complexity patients. Output also significantly impacted on EDQPI, particularly the capacity to reduce the LOS of admitted patients.

Use of a comprehensive metabolic panel point-of-care test to reduce length of stay in the emergency department: a randomized controlled trial

STUDY OBJECTIVE

Awaiting results from laboratory testing may sometimes be a rate-limiting step in emergency department (ED) throughput prolonging length of stay and contributing to crowding. We determine whether introduction of a comprehensive metabolic panel point-of-care test can reduce ED length of stay compared with traditional central laboratory testing.

METHODS

We performed a randomized, controlled trial among 10,244 noncritically ill ED patients aged 15 years and older whose physicians ordered a comprehensive metabolic panel at a single, large, academic, urban medical center. Participants were randomly assigned to performance of a comprehensive metabolic panel by a point-of-care test (n=5,154) or central laboratory testing (n=5,090). The primary outcome was length of stay in the ED.

RESULTS

A point-of-care test reduced median ED length of stay among all study patients by 22 minutes (median 350 minutes [interquartile range 206 to 1,002 minutes] with point-of-care test versus median 372 minutes [interquartile range 217 to 1,150 minutes] with central laboratory testing; median difference 22 minutes; 95% confidence interval [CI] 4 to 40 minutes). A point-of-care test also reduced ED length of stay in patients discharged to home (256 versus 268 minutes; median difference 12 minutes; 95% CI 2 to 22 minutes) and with an Emergency Severity Index triage level of 3 (333 versus 355 minutes; median difference 22 minutes; 95% CI 4 to 40 minutes).

CONCLUSION

Use of a point-of-care test for a comprehensive metabolic panel reduced ED length of stay compared with central laboratory testing in the adult ED of a single academic center.

Patterns and factors associated with intensive use of ED services: implications for allocating resources

AIM

This study aims to better understand the patterns and factors associated with the use of emergency department (ED) services on high-volume and intensive (defined by high volume and high-patient severity) days to improve resource allocation and reduce ED overcrowding.

METHODS

This study created a new index of "intensive use" based on the volume and severity of illness and a 3-part categorization (normal volume, high volume, intensive use) to measure stress in the ED environment. This retrospective, cross-sectional study collected data from hospital clinical and financial records of all patients seen in 2001 at an urban academic hospital ED.

RESULTS

Multiple logistic regression models identified factors associated with high volume and intensive use. Factors associated with intensive days included being in a motor vehicle crash; having a gun or stab wound; arriving during the months of January, April, May, or August; and arriving during the days of Monday, Tuesday, or Wednesday. Factors associated with high-volume days included falling from 0 to 10 ft; being in a motor vehicle crash; arriving during the months of January, April, May, or August; and arriving during the days of Monday, Tuesday, or Wednesday.

CONCLUSION

These findings offer inputs for reallocating resources and altering staffing models to more efficiently provide high-quality ED services and prevent overcrowding.

Boarding inpatients in the emergency department increases discharged patient length of stay

BACKGROUND

Boarding of inpatients in the Emergency Department (ED) has been widely recognized as a major contributor to ED crowding and a cause of adverse outcomes. We hypothesize that these deleterious effects extend to those patients who are discharged from the ED by increasing their length of stay (LOS).

STUDY OBJECTIVES

This study investigates the impact of boarding inpatients on the ED LOS of discharged patients.

METHODS

This retrospective, observational, cohort study investigated the association between ED boarder burden and discharged patient LOS over a 3-year period in an urban, academic tertiary care ED. Median ED LOS of 179,840 discharged patients was calculated for each quartile of the boarder burden at time of arrival, and Spearman correlation coefficients were used to summarize the relationship. Subgroup analyses were conducted, stratified by patient acuity defined by triage designation, and hour of arrival.

RESULTS

Overall median discharged patient ED LOS increased by boarder burden quartile (205 [95% confidence interval (CI) 203-207], 215 [95% CI 214-217], 221 [95% CI 219-223], and 221 [95% CI 219-223] min, respectively), with a Spearman correlation of 0.25 between daily total boarder burden hours and median LOS. When stratified by patient acuity and hour of arrival (11:00 a.m.-11:00 p.m.), LOS of medium-acuity patients increased significantly by boarder burden quartile (252 [95% CI 247-255], 271 [95% CI 267-275], 285 [95% CI 95% CI 278-289], and 309 [95% CI 305-315] min, respectively) with a Spearman correlation of 0.18.

CONCLUSION

In this retrospective study, increasing boarder burden was associated with increasing LOS of patients discharged from the ED, with the greatest effect between 11:00 a.m. and 11:00 p.m. on medium-acuity patients. This relationship between LOS and ED capacity limitation by inpatient boarders has important implications, as ED and hospital leadership increasingly focus on ED LOS as a measure of efficiency and throughput.

Demand at the emergency department front door: 10-year trends in presentations

OBJECTIVES

To measure the increase in volume and age-specific rates of presentations to public hospital emergency departments (EDs), as well as any changes in ED length of stay (LOS); and to describe trends in ED utilisation.

DESIGN, PATIENTS AND SETTING

Population-based retrospective analysis of Department of Health public hospital ED data for metropolitan Melbourne for 1999-00 to 2008-09.

MAIN OUTCOME MEASURES

Presentation numbers; presentation rates per 1000 person-years; ED LOS.

RESULTS

ED presentations increased from 550,662 in 1999-00 to 853,940 in 2008-09. This corresponded to a 32% rise in rate of presentation (95% CI, 29%-35%), an average annual increase of 3.6% (95% CI, 3.4%-3.8%) after adjustment for population changes. Almost 40% of all patients remained in the ED for ≥4 hours in 2008-09, with LOS increasing over time for patients who were more acutely unwell. The likelihood of presentation rose with increasing age, with people aged≥85 years being 3.9 times as likely to present as those aged 35-59 years (95% CI, 3.8-4.0). The volume of older people presenting more than doubled over the decade. They were more likely to arrive by emergency ambulance and were more acutely unwell than 35-59 year olds, with 75% having an LOS≥4 hours and 61% requiring admission in 2008-09.

CONCLUSION

The rise in presentation numbers and presentation rates per 1000 person-years over 10 years was beyond that expected from demographic changes. Current models of emergency and primary care are failing to meet community needs at times of acute illness. Given these trends, the proposed 4-hour targets in 2012 may be unachievable unless there is significant redesign of the whole system.

Exogenous predictors of national performance measures for emergency department crowding

STUDY OBJECTIVE

We explore the relationship between exogenous-level predictors and performance on 4 emergency department (ED) throughput measures approved by the National Quality Forum: median ED length of visit for admitted and discharged patients, median waiting time, and rate of left without being seen. We seek to find predictors for benchmarking and public reporting.

METHODS

This was a study of 424 US hospitals that reported data to the National Hospital Ambulatory Care Survey in 2008 to 2009. Wald F tests and generalized linear models were used to test the relationship between exogenous variables (case mix, age mix, ED volume, teaching status, and Metropolitan Statistical Area status) and performance on the measures.

RESULTS

Median waiting time was 35 minutes (95% confidence interval [CI] 26 to 43 minutes), median length of visit for patients treated but not admitted was 131 minutes (95% CI 121 to 142 minutes), median length of visit for patients admitted was 244 minutes (95% CI 218 to 270 minutes), and rate of left without being seen was 1.3% (95% CI 0.9% to 1.8%). Most exogenous variables, including ED volume, Metropolitan Statistical Area, teaching hospital status, age mix, and case mix, demonstrated significant association with waiting times and lengths of visit. Older age and a higher proportion of respiratory complaints were associated with differences in rates of left without being seen.

CONCLUSION

Several exogenous factors outside of a hospital's control are associated with National Quality Forum-approved ED performance measures, which will have important implications for future benchmarking and public reporting of these data.

Electronic information exchange between emergency departments and poison control centers: a Delphi study

CONTEXT

The US emergency departments and poison control centers use telephone communication to exchange information about poison exposed patients. Electronically exchanged patient information could better support care for poisoned patients by improving information availability for decision making and by decreasing unnecessary emergency department telephone interruptions. As federal initiatives push to increase clinical health information exchange (HIE), it is essential to assess the readiness of US poison control centers. We conducted a nationwide Delphi study to determine consensus on legal, operational, and clinical considerations that are important for electronic information exchange between emergency departments and poison control centers.

MATERIALS AND METHODS

A national panel of US experts (n = 71) in emergency medicine and poison control participated in a Delphi study, September-December 2010. Panelists rated statements describing concepts related to implementation, adoption, or potential outcomes of electronic information exchange between emergency departments and poison control centers. The statements reflected panelist responses to initial open-ended questions and literature-based concepts.

RESULTS

A total of 71 panelists agreed to participate. The response rate for each round ranged from 0.73 to 0.77. Most (114/121) statements reached consensus. Seven statements failed to reach consensus. Panelists indicated that user involvement in the design of systems and tools is important. Workflow integration, safety, evidence of benefit, and outcomes are high-importance issues.

DISCUSSION/CONCLUSIONS

Future research and development related to electronic information exchange should address high-importance issues: safety, patient outcomes, workflow integration, and evidence of benefit. It should also address key barriers: initial and ongoing costs associated with electronic information exchange, the absence of software and tools to facilitate exchange, and the need for training. Users should be involved in the design of an electronic information exchange process, and the process should support, not replace, verbal communication.

National study of antibiotic use in emergency department visits for pneumonia, 1993 through 2008

OBJECTIVES

The Infectious Disease Society of America (IDSA) and American Thoracic Society (ATS) developed guidelines for the management of community-acquired pneumonia (CAP); however, there are sparse data on actual rates of antibiotic use in the emergency department (ED) setting.

METHODS

Data were obtained from the National Hospital Ambulatory Medical Care Survey (NHAMCS) for ED visits during 1993 through 2008 for adults with a diagnosis of pneumonia.

RESULTS

During the study period there were an estimated 23,252,000 pneumonia visits, representing 1.8% of all ED visits. The visit rate for pneumonia during this 16-year period may have increased (p trend = 0.055). Overall, 66% of adult patients with a primary diagnosis of pneumonia had documentation of an antibiotic administered while in the ED. There was an increase in antibiotic administration for adults with pneumonia from 1993 through 2008 (49% to 80%; p trend < 0.001). Specifically, there was an increase in use of macrolides from 1993 to 2006 (20% to 30%, p trend < 0.001) and a marked increase in use of quinolones from 0% to 39% from 1993 through 2008 (p trend < 0.001). Penicillin and cephalosporin use remained stable. Use of an antibiotic consistent with 2007 IDSA/ATS guidelines increased from 22% (95% confidence interval [CI] = 16% to 27%) of cases in 1993-1994 to 68% (95% CI = 63% to 73%) of cases in 2007-2008 (p trend < 0.001).

CONCLUSIONS

ED visit rates for pneumonia increased slightly from 1993 through 2008. Although antibiotic administration in the ED has increased for adults with CAP, guideline-concordant antibiotics may not be consistently administered.

Combination of copeptin and troponin assays to rapidly rule out non-ST elevation myocardial infarction in the emergency department

OBJECTIVES

The aim of this study was to analyze the diagnostic accuracy and the clinical usefulness of the combination of troponin I (cTnI) and copeptin measured at presentation with an automated assay to rapidly rule out non-ST elevation myocardial infarction (NSTEMI) in patients with suspected cardiac chest pain presenting to an emergency department (ED).

METHODS

This study was an ancillary analysis of a prospective observational study. Copeptin and cTnI levels were sampled at presentation in 641 consecutive patients admitted to the ED for chest pain with onset within the last 12 hours and without ST elevation on a 12-lead electrocardiogram (ECG). Copeptin was measured with an automated assay and troponin with conventional assay. The performance of a combination of cTnI and copeptin for NSTEMI diagnosis was studied, the clinical utility was assessed by multivariate analysis, and an area under the curve (AUC) calculation was used to determine accuracy.

RESULTS

NSTEMI was diagnosed in 95 patients (15%). The sensitivity and negative predictive value (NPV) of the combination of copeptin and cTnI measures were 90.4% (95% confidence interval [CI] = 88.2% to 92.7%) and 97.6% (95% CI = 96.4% to 98.7%) versus 55.3% (95% CI = 51.5% to 59.2%) and 92.8% (95% CI = 90.8% to 94.8%) with cTnI alone. The AUC of the combination of copeptin and cTnI was 0.89 (95% CI = 0.85% to 0.92%) and was significantly higher than the AUC of cTnI alone (0.77, 95% CI = 0.72% to 0.82%, p < 0.05). The patient classification was slightly improved when copeptin was added to the usual diagnostic tools used for NSTEMI management.

CONCLUSIONS

In this study, determination of copeptin, in addition to cTnI, improves early diagnostic accuracy of NSTEMI. However, the sensitivity of this combination even using a conventional troponin assay remains insufficient to safely rule out NSTEMI at the time of presentation.

MATHEMATICAL MODELING: THE CASE OF EMERGENCY DEPARTMENT WAITING TIMES

A decision analytic model often comprises a significant part of a health technology assessment. As health technology assessment in the hospital setting evolves, there is an increased need for modeling methods that account for patient care pathways and interactions between patients and their environment. For example, an evaluation of a computed tomography (CT) scanner for a new indication would need to consider the current and increased demand of the machine and how that may affect service in other areas of the hospital. This problem solving approach views “problems” through a systems perspective.

Emergency department volume and racial and ethnic differences in waiting times in the United States

BACKGROUND

Racial and ethnic differences in emergency department (ED) waiting times have been observed previously.

OBJECTIVES

We explored how adjusting for ED attributes, particularly visit volume, affected racial/ethnic differences in waiting time.

RESEARCH DESIGN

We constructed linear models using generalized estimating equations with 2007-2008 National Hospital Ambulatory Medical Care Survey data.

SUBJECTS

We analyzed data from 54,819 visits to 431 US EDs.

MEASURES

Our dependent variable was waiting time, measured from arrival to time seen by physician, and was log transformed because it was skewed. Primary independent variables were individual race/ethnicity (Hispanic and non-Hispanic white, black, other) and ED race/ethnicity composition (covariates for percentages of Hispanics, blacks, and others). Covariates included patient age, triage assessment, arrival by ambulance, payment source, volume, region, and teaching hospital.

RESULTS

Geometric mean waiting times were 27.3, 37.7, and 32.7 minutes for visits by white, black, and Hispanic patients. Patients waited significantly longer at EDs serving higher percentages of black patients; per 25 point increase in percent black patients served, waiting times increased by 23% (unadjusted) and 13% (adjusted). Within EDs, black patients waited 9% (unadjusted) and 4% (adjusted) longer than whites. The ED attribute most strongly associated with waiting times was visit volume. Waiting times were about half as long at low-volume compared with high-volume EDs (P<0.001). For Hispanic patients, differences were smaller and less robust to model choice.

CONCLUSIONS

Non-Hispanic black patients wait longer for ED care than whites primarily because of where they receive that care. ED volume may explain some across-ED differences.

Emergency department crowding and risk of preventable medical errors

The objective of the study is to determine the association between emergency department (ED) crowding and preventable medical errors (PME). This was a retrospective cohort study of 533 ED patients enrolled in the National ED Safety Study (NEDSS) in four Massachusetts EDs. Individual patients' average exposure to ED crowding during their ED visit was compared with the occurrence of a PME (yes/no) for the three diagnostic categories in NEDSS: acute myocardial infarction, asthma exacerbation, and dislocation requiring procedural sedation. To accommodate site-to-site differences in available administrative data, ED crowding was measured using one of three previously validated crowding metrics (ED Work Index, ED Workscore, and ED Occupancy). At each site, the continuous measure was placed into site-specific quartiles, and these quartiles then were combined across sites. We found that 46 (8.6%; 95% confidence interval, 6.4-11.3%) of the 533 patients experienced a PME. For those seen during higher levels of ED crowding (quartile 4 vs. quartile 1), the occurrence of PMEs was more than twofold higher, both on unadjusted analysis and adjusting for two potential confounders (diagnosis, site). The association appeared non-linear, with most PMEs occurring at the highest crowding level. We identified a direct association between high levels of ED crowding and risk of preventable medical errors. Further study is needed to determine the generalizability of these results. Should such research confirm our findings, we would suggest that mitigating ED crowding may reduce the occurrence of preventable medical errors.

High hospital occupancy is associated with increased risk for patients boarding in the emergency department

BACKGROUND

Boarding admitted patients in the emergency department due to high hospital occupancy is a worldwide problem. However, whether or not emergency department-boarded patients managed by emergency department providers subjects them to increased serious complications needs further clarification.

METHODS

A multivariate logistic regression analysis was used to examine the relationship of patient's age, sex, arrival hours, diagnostic category, triage category, daily emergency department visits, and daily hospital occupancy to the occurrence of serious complications within 24 hours for 20,276 emergency admissions in a 4-year period.

RESULTS

A vast majority of study days (86.5%) saw very high occupancy ≥90%. Serious complications incidence was 13.62 per 1000 patient days when hospital occupancy was ≤90%, and it increased significantly to 17.10 and 22.52 per 1000 patient days for occupancy at 90%-95% and ≥95%, respectively. In the multivariate analysis, significant risk factors for serious complications included daily occupancy ≥95% (adjusted odds ratio [OR] 1.73; 95% confidence interval [CI], 1.26-2.39), triage category (adjusted OR 0.20; 95% CI, 0.17-0.24), and specific diagnoses (injury and poisoning [adjusted OR 1.62; 95% CI, 1.22-2.84], respiratory [adjusted OR 2.48; 95% CI, 1.37-4.49], and circulatory [adjusted OR 3.24; 95% CI, 1.80-5.80]).

CONCLUSION

High hospital occupancy was associated with an increased incidence of serious complications within 24 hours for patients admitted but still boarded in the emergency department and managed by emergency department providers.

Using Data to Drive Emergency Department Design: A Metasynthesis

Objective:

There has been an uptick in the field of emergency department (ED) operations research and data gathering, both published and unpublished. This new information has implications for ED design. The specialty suffers from an inability to have these innovations reach frontline practitioners, let alone design professionals and architects. This paper is an attempt to synthesize for design professionals the growing data regarding ED operations.

Methods:

The following sources were used to capture and summarize the research and data collections available regarding ED operations: the Emergency Department Benchmarking Alliance database; a literature search using both PubMed and Google Scholar search engines; and data presented at conferences and proceedings.

Results:

Critical information that affects ED design strategies is summarized, organized, and presented. Data suggest an optimal size for ED functional units. The now-recognized arrival and census curves for the ED suggest a department that expands and contracts in response to changing census. Operational improvements have been clearly identified and are grouped into three categories: input, throughput, and outflow. Applications of this information are suggested.

Conclusion:

The sentinel premise of this meta-synthesis is that data derived from improvement work in the area of ED operations has applications for ED design. EDs can optimize their functioning by marrying good processes and operations to good design. This review paper is an attempt to bring this new information to the attention of the multidisciplinary team of architects, designers, and clinicians.

Rapid medical assessment: improving pediatric emergency department time to provider, length of stay, and left without being seen rates

OBJECTIVES

This article aimed to study the impact of a rapid medical assessment (RMA) program on patient flow and left without being seen (LWBS) rates in a pediatric emergency department (ED). RMA is designed to evaluate and discharge uncomplicated patients quickly or initiate diagnostic workup and treatment before the patient is placed in an ED bed.

METHODS

Rapid medical assessment was initiated January 1, 2008 with an assigned midlevel provider. We compared 6 months of data from January 1 to June 30, 2007 (pre-RMA), to January 1 to June 30, 2008 (post-RMA). Data studied were obtained from a tracking system and include the time to provider, ED length of stay, and the LWBS rate. t Test was used to compare results, and χ test was used to compare LWBS rates.

RESULTS

During the study period, there were 28,360 patients seen in 2007 and 32,053 in 2008. Time to provider mean time was 80 minutes (median = 57) in 2007 and 53 minutes (median = 39) in 2008, with a difference of 27 minutes (95% confidence interval, 25-28 minutes). Mean length of stay in 2007 was 239 minutes (median = 220) compared to 181 minutes (median = 162) in 2008, with a difference of 58 minutes (95% confidence interval, 56-60 minutes). The LWBS rate decreased from 9% in 2007 to 3% in 2008 (χ P < 0.01).

CONCLUSIONS

Rapid medical assessment is an effective way to improve patient flow and reduce the LWBS rate. A decrease in the LWBS rate allows the ED to provide health care to these potentially high-risk patients.

Selection and validation of quality indicators for the Shorter Stays in Emergency Departments National Research Project

OBJECTIVE

Despite the spread of time targets for ED lengths of stay around the world, there have been few studies exploring the effects of such policies on quality of ED care. The Shorter Stays in Emergency Departments (SSED) National Research Project seeks to address this. The purpose of this paper was to describe how the indicators for the SSED study in New Zealand were selected and validated.

METHODS

A literature review was used to identify potential indicators. A reference group of 25 key stakeholders from across the health system was convened, with the aims of validating the suggested indicators and to ensure that other candidate indicators were not overlooked. A thematic analysis using a general inductive approach was used to analyse focus group discussions.

RESULTS

The major themes were communication, access, timeliness, appropriateness and satisfaction. The 12 indicators selected after literature review were confirmed and two further indicators added after the thematic analysis. The indicators are: hospital and ED length of stay; re-presentation within 48 h; mortality; times to reperfusion, antibiotics, asthma treatment, analgesia, CT for head injury and to theatre (appendicitis and fractured neck of femur); triage time compliance; proportion who left without being seen; quality of discharge information; and ED overcrowding/access block.

CONCLUSION

Through literature review and consultation with stakeholders, an evidence-based and clinically relevant set of indicators was compiled with which to measure the effect of the SSED target. This indicator set is consistent with recent international recommendations for measuring quality of care in EDs.

Impact of physician screening in the emergency department on patient flow

BACKGROUND

Physician triage is one of many front-end interventions being implemented to improve emergency department (ED) efficiency.

STUDY OBJECTIVE

We aim to determine the impact of this intervention on some key components of ED patient flow, including time to physician evaluation, treatment order entry, diagnostic order entry, and disposition time for admitted patients.

METHODS

We conducted a 2-year before-after analysis of a physician triage system at an urban tertiary academic center with 90,000 annual visits. The goal of the physician in triage was to arrange safe disposition of straightforward patients as well as to initiate work-ups. All medium-acuity patients arriving during the hours of the intervention were impacted and thus included in the analysis. Our primary outcome was the time to disposition decision. In addition to before-after analysis, comparison was made with high-acuity patients, a group not impacted by this intervention. Patient flow data were extracted from the ED information system. Outcomes were summarized with medians and interquartiles. Multivariable regression analysis was performed to investigate the intervention effect controlling for potential confounding variables.

RESULTS

The median time to disposition decision decreased by 6min, and the time to physician evaluation, analgesia, antiemetic, antibiotic, and radiology order decreased by 16, 70, 66, 36, and 16min, respectively. These findings were all statistically significant. Similar results were observed from the multivariable regression models after controlling for potential confounding factors.

CONCLUSIONS

Physician triage led to earlier evaluation, physician orders, and a decrease in the time to disposition decision.

Implementing performance improvement in New Zealand emergency departments: the six hour time target policy national research project protocol

BACKGROUND

In May 2009, the New Zealand government announced a new policy aimed at improving the quality of Emergency Department care and whole hospital performance. Governments have increasingly looked to time targets as a mechanism for improving hospital performance and from a whole system perspective, using the Emergency Department waiting time as a performance measure has the potential to see improvements in the wider health system. However, the imposition of targets may have significant adverse consequences. There is little empirical work examining how the performance of the wider hospital system is affected by such a target. This project aims to answer the following questions: How has the introduction of the target affected broader hospital performance over time, and what accounts for these changes? Which initiatives and strategies have been successful in moving hospitals towards the target without compromising the quality of other care processes and patient outcomes? Is there a difference in outcomes between different ethnic and age groups? Which initiatives and strategies have the greatest potential to be transferred across organisational contexts?

METHODS/DESIGN

The study design is mixed methods; combining qualitative research into the behaviour and practices of specific case study hospitals with quantitative data on clinical outcomes and process measures of performance over the period 2006-2012. All research activity is guided by a Kaupapa Māori Research methodological approach. A dynamic systems model of acute patient flows was created to frame the study. Consequences of the target (positive and negative) will be explored by integrating analyses and insights gained from the quantitative and qualitative streams of the study.

DISCUSSION

At the time of submission of this protocol, the project has been underway for 12 months. This time was necessary to finalise both the case study sites and the secondary outcomes through key stakeholder consultation. We believe that this is an appropriate juncture to publish the protocol, now that the sites and final outcomes to be measured have been determined.

Understanding the critical role of social work in safety net medical settings: framework for research and practice in the emergency department

Social workers in Emergency Departments (ED) provide counseling, community resource linkage, and discharge planning. The ED is a critical intervention point for patients with multiple unmet medical, psychological, and social needs, and little or no other contact with service providers. In part because of its role as a medical safety net for underserved populations, use of the ED has steadily increased over time. There is limited research examining the utility of social services in the ED. This article provides a brief history of hospital social work and a literature review of ED social work research with the goal of advancing current research and practice agendas.

International perspectives on emergency department crowding

The maturation of emergency medicine (EM) as a specialty has coincided with dramatic increases in emergency department (ED) visit rates, both in the United States and around the world. ED crowding has become a public health problem where periodic supply and demand mismatches in ED and hospital resources cause long waiting times and delays in critical treatments. ED crowding has been associated with several negative clinical outcomes, including higher complication rates and mortality. This article describes emergency care systems and the extent of crowding across 15 countries outside of the United States: Australia, Canada, Denmark, Finland, France, Germany, Hong Kong, India, Iran, Italy, The Netherlands, Saudi Arabia, Catalonia (Spain), Sweden, and the United Kingdom. The authors are local emergency care leaders with knowledge of emergency care in their particular countries. Where available, data are provided about visit patterns in each country; however, for many of these countries, no national data are available on ED visits rates or crowding. For most of the countries included, there is both objective evidence of increases in ED visit rates and ED crowding and also subjective assessments of trends toward higher crowding in the ED. ED crowding appears to be worsening in many countries despite the presence of universal health coverage. Scandinavian countries with robust systems to manage acute care outside the ED do not report crowding is a major problem. The main cause for crowding identified by many authors is the boarding of admitted patients, similar to the United States. Many hospitals in these countries have implemented operational interventions to mitigate crowding in the ED, and some countries have imposed strict limits on ED length of stay (LOS), while others have no clear plan to mitigate crowding. An understanding of the causes and potential solutions implemented in these countries can provide a lens into how to mitigate ED crowding in the United States through health policy interventions and hospital operational changes.

Emergency department crowding is associated with decreased quality of analgesia delivery for children with pain related to acute, isolated, long-bone fractures

OBJECTIVES

The authors sought to determine which quality measures of analgesia delivery are most influenced by emergency department (ED) crowding for pediatric patients with long-bone fractures.

METHODS

This cross-sectional, retrospective study included patients 0-21 years seen for acute, isolated long-bone fractures, November 2007 to October 2008, at a children's hospital ED. Nine quality measures were studied: six were based on the timeliness (1-hour receipt) and effectiveness (receipt/nonreceipt) of three fracture-related processes: pain score, any analgesic, and opioid analgesic administration. Three equity measures were also tested: language, identified primary care provider (PCP), and insurance. The primary independent variable was a crowding measure: ED occupancy. Models were adjusted for age, language, insurance, identified PCP, triage level, ambulance arrival, and time of day. The adjusted risk of each timeliness or effectiveness quality measure was measured at five percentiles of crowding and compared to the risk at the 10th and 90th percentiles. The role of equity measures as moderators of the crowding-quality models was tested.

RESULTS

The study population included 1,229 patients. Timeliness and effectiveness quality measures showed an inverse association with crowding-an effect not moderated by equity measures. Patients were 4% to 47% less likely to receive timely care and were 3% to 17% less likely to receive effective care when each crowding measure was at the 90th than at the 10th percentile (p < 0.05). For three of the six quality measures, quality declined steeply between the 75th and 90th crowding percentiles.

CONCLUSIONS

Crowding is associated with decreased timeliness and effectiveness, but not equity, of analgesia delivery for children with fracture-related pain.

Review of modeling approaches for emergency department patient flow and crowding research

Emergency department (ED) crowding is an international phenomenon that continues to challenge operational efficiency. Many statistical modeling approaches have been offered to describe, and at times predict, ED patient load and crowding. A number of formula-based equations, regression models, time-series analyses, queuing theory-based models, and discrete-event (or process) simulation (DES) models have been proposed. In this review, we compare and contrast these modeling methodologies, describe the fundamental assumptions each makes, and outline the potential applications and limitations for each with regard to usability in ED operations and in ED operations and crowding research.

Achieving efficiency in crowded emergency departments: a research agenda

In 2011, Academic Emergency Medicine convened a consensus conference entitled "Interventions to Assure Quality in the Crowded Emergency Department." This article, a product of the breakout session on "interventions to safeguard efficiency of care," explores various elements of the research agenda on efficiency and quality in crowded emergency departments (EDs). The authors discuss four areas identified as critical to achieving progress in the research agenda for improving ED efficiency: 1) What measures can be used to understand and improve the efficiency and quality of interventions in the ED? 2) Which factors outside of the ED's control affect ED efficiency? 3) How do workforce factors affect ED efficiency? 4) How do ED design, patient flow structures, and use of technology affect efficiency? Filling these knowledge gaps is vital to identifying interventions that improve the delivery of emergency care in all EDs.

Practical implications of implementing emergency department crowding interventions: summary of a moderated panel

Emergency department (ED) crowding continues to be a major public health problem in the United States and around the world. In June 2011, the Academic Emergency Medicine consensus conference focused on exploring interventions to alleviate ED crowding and to generate a series of research agendas on the topic. As part of the conference, a panel of leaders in the emergency care community shared their perspectives on emergency care, crowding, and some of the fundamental issues facing emergency care today. The panel participants included Drs. Bruce Siegel, Sandra Schneider, Peter Viccellio, and Randy Pilgrim. The panel was moderated by Dr. Jesse Pines. Dr. Siegel's comments focused on his work on Urgent Matters, which conducted two multihospital collaboratives related to improving ED crowding and disseminating results. Dr. Schneider focused on the future of ED crowding measures, the importance of improving our understanding of ED boarding and its implications, and the need for the specialty of emergency medicine (EM) to move beyond the discussion of unnecessary visits. Dr. Viccellio's comments focused on several areas, including the need for a clear message about unnecessary ED visits by the emergency care community and potential solutions to improve ED crowding. Finally, Dr. Pilgrim focused on the effect of effective leadership and management in crowding interventions and provided several examples of how these considerations directly affected the success or failure of well-constructed ED crowding interventions. This article describes each panelist's comments in detail.

The association between length of emergency department boarding and mortality

OBJECTIVES

Emergency department (ED) boarding has been associated with several negative patient-oriented outcomes, from worse satisfaction to higher inpatient mortality rates. The current study evaluates the association between length of ED boarding and outcomes. The authors expected that prolonged ED boarding of admitted patients would be associated with higher mortality rates and longer hospital lengths of stay (LOS).

METHODS

This was a retrospective cohort study set at a suburban academic ED with an annual ED census of 90,000 visits. Consecutive patients admitted to the hospital from the ED and discharged between October 2005 and September 2008 were included. An electronic medical record (EMR) system was used to extract patient demographics, ED disposition (discharge, admit to floor), ED and hospital LOS, and in-hospital mortality. Boarding was defined as ED LOS 2 hours or more after decision for admission. Descriptive statistics were used to evaluate the association between length of ED boarding and hospital LOS, subsequent transfer to an intensive care unit (ICU), and mortality controlling for comorbidities.

RESULTS

There were 41,256 admissions from the ED. Mortality generally increased with increasing boarding time, from 2.5% in patients boarded less than 2 hours to 4.5% in patients boarding 12 hours or more (p < 0.001). Mean hospital LOS also showed an increase with boarding time (p < 0.001), from 5.6 days (SD ± 11.4 days) for those who stayed in the ED for less than 2 hours to 8.7 days (SD ± 16.3 days) for those who boarded for more than 24 hours. The increases were still apparent after adjustment for comorbid conditions and other factors.

CONCLUSIONS

Hospital mortality and hospital LOS are associated with length of ED boarding.

Interventions to improve the timeliness of emergency care

With a persistent trend of increasing emergency department (ED) volumes every year, services are intensifying. Thus, improving the timeliness of delivering emergency care should be a primary focus, both from an operational and from a research perspective. Much has been published on factors associated with delays in emergency care, and the next phase in this area of research will focus on exploring interventions to improve the timeliness of care. On June 1, 2011, Academic Emergency Medicine held a consensus conference titled "Interventions to Assure Quality in the Emergency Department." This article summarizes the findings of the breakout session that investigated interventions to improve the timeliness of emergency care. This article will explore the background on the concept of timeliness of emergency care, the current state of interventions that have been implemented to improve timeliness, and specific questions as a framework for a future research agenda.

Consensus-based recommendations for research priorities related to interventions to safeguard patient safety in the crowded emergency department

This article describes the results of the Interventions to Safeguard Safety breakout session of the 2011 Academic Emergency Medicine (AEM) consensus conference entitled "Interventions to Assure Quality in the Crowded Emergency Department." Using a multistep nominal group technique, experts in emergency department (ED) crowding, patient safety, and systems engineering defined knowledge gaps and priority research questions related to the maintenance of safety in the crowded ED. Consensus was reached for seven research priorities related to interventions to maintain safety in the setting of a crowded ED. Included among these are: 1) How do routine corrective processes and compensating mechanism change during crowding? 2) What metrics should be used to determine ED safety? 3) How can checklists ensure safer care and what factors contribute to their success or failure? 4) What constitutes safe staffing levels/ratios? 5) How can we align emergency medicine (EM)-specific patient safety issues with national patient safety issues? 6) How can we develop metrics and skills to recognize when an ED is getting close to catastrophic overload conditions? and 7) What can EM learn from experts and modeling from fields outside of medicine to develop innovative solutions? These priorities have the potential to inform future clinical and human factors research and extramural funding decisions related to this important topic.

Comparison of methods for measuring crowding and its effects on length of stay in the emergency department

OBJECTIVES

This consensus conference presentation article focuses on methods of measuring crowding. The authors compare daily versus hourly measures, static versus dynamic measures, and the use of linear or logistic regression models versus survival analysis models to estimate the effect of crowding on an outcome.

METHODS

Emergency department (ED) visit data were used to measure crowding and completion of waiting room time, treatment time, and boarding time for all patients treated and released or admitted to a single ED during 2010 (excluding patients who left without being seen). Crowding was characterized according to total ED census. First, total ED census on a daily and hourly basis throughout the 1-year study period was measured, and the ratios of daily and hourly census to the ED's median daily and hourly census were computed. Second, the person-based ED visit data set was transposed to person-period data. Multiple records per patient were created, whereby each record represented a consecutive 15-minute interval during each patient's ED length of stay (LOS). The variation in crowding measured statically (i.e., crowding at arrival or mean crowding throughout the shift in which the patient arrived) or dynamically (every 15 minutes throughout each patient's ED LOS) were compared. Within each phase of care, the authors divided each individual crowding value by the median crowding value of all 15-minute intervals to create a time-varying ED census ratio. For the two static measures, the ratio between each patient's ED census at arrival and the overall median ED census at arrival was computed, as well as the ratio between the mean shift ED census (based on the shift in which the patient arrived) and the study ED's overall mean shift ED census. Finally, the effect of crowding on the probability of completing different phases of emergency care was compared when estimated using a log-linear regression model versus a discrete time survival analysis model.

RESULTS

During the 1-year study period, for 9% of the hours, total ED census was at least 50% greater than the median hourly census (median, 36). In contrast, on none of the days was total ED census at least 50% greater than the median daily census (median, 161). ED census at arrival and time-varying ED census yielded greater variation in crowding exposure compared to mean shift census for all three phases of emergency care. When estimating the effect of crowding on the completion of care, the discrete time survival analysis model fit the observed data better than the log-linear regression models. The discrete time survival analysis model also determined that the effect of crowding on care completion varied during patients' ED LOS.

CONCLUSIONS

Crowding measured at the daily level will mask much of the variation in crowding that occurs within a 24-hour period. ED census at arrival demonstrated similar variation in crowding exposure as time-varying ED census. Discrete time survival analysis is a more appropriate approach for estimating the effect of crowding on an outcome.