Advanced statistics: developing a formal model of emergency department census and defining operational efficiency

BACKGROUND

Emergency department (ED) crowding has been a frequent topic of investigation, but it is a concept without an objective definition. This has limited the scope of research and progress toward the development of consistent and meaningful operational responses.

OBJECTIVES

To develop a straightforward model of ED census that incorporates concepts of ED crowding, daily patient surge, throughput time, and operational efficiency.

METHODS

Using 2005-2006 patient encounter data at a Level 1 urban trauma center, a set of three stylized facts describing daily patterns of ED census was observed. These facts guided the development of a formal, mathematical model of ED census. Using this model, a metric of ED operational efficiency and a forecast of ED census were developed.

RESULTS

The three stylized facts of daily ED census were 1) ED census is cyclical, 2) ED census exhibits an input-output relationship, and 3) unexpected shocks have long-lasting effects. These were represented by a three-equation system. This system was solved for the following expression, Census(t) = A(.) + B(.) cos(vT + epsilon) + a(e(t)), that captured the time path of ED census. Using nonlinear estimation, the parameters of this expression were estimated and a forecasting tool was developed.

CONCLUSIONS

The basic pattern of ED census can be represented by a straightforward expression. This expression can be quickly adapted to a variety of inquiries regarding ED crowding, daily surge, and operational efficiency.

Easing the Strain on a Pediatric Tertiary Care Center

OBJECTIVE

To evaluate the ability of a regionalized system to safely transfer patients requiring admission from a referral center to either regional or community hospitals.

DESIGN

Cohort study of children requiring admission. Following transfer, a questionnaire was administered to eligible caregivers. Subsequent emergency department (ED) use was assessed by comparing children who were transferred with those who were not.

SETTING

The Hospital for Sick Children, Toronto, Ontario, Canada, from April 1, 2003, through March 31, 2004.

PARTICIPANTS

Caregivers of 371 children who underwent transfer from a tertiary care center ED to either a regional or a community hospital were eligible; 344 were contacted. Two hundred fifty-three children for whom transfer was considered but was not performed served as a comparison group. Intervention Questionnaire administered to caregivers, combined with database review.

MAIN OUTCOME MEASURES

Failure of the transfer process, caregiver satisfaction, and future tertiary care center ED use.

RESULTS

Five children experienced intravenous access problems, and 4 children experienced delayed antibiotic administration. Caregiver satisfaction was 92.3% with the transfer process and 84.4% with the care at the receiving hospital. Forty-seven percent of caregivers indicated that they would agree to a similar transfer in the future. Two years later, fewer transferred children (39.9%) than those who were not transferred (49.6%) had revisited the tertiary care center ED (odds ratio, 1.52; 95% confidence interval, 1.10-2.10). The mean number of visits was unchanged (95% confidence interval of the difference, -0.44 to 0.21 visits).

CONCLUSIONS

Although we found the redistribution program to be safe, caregivers stated a preference not to be transferred again. The redistribution system did not substantially alter tertiary care center ED use.

Predictors of Mortality Following Involuntary Interinstitutional Relocation

Relocation is traumatic for older adults. There is a paucity of literature about the characteristics of individuals who are most susceptible to negative effects of relocation. Residents of a nursing home that closed were compared with residents of a control institution to determine whether relocation had a significant effect on mortality and to identify risk factors for death. The difference in mortality was significant. A Cox regression model demonstrated that the only variable to achieve significance in predicting mortality was the relocation itself. Research must evaluate strategies that will reduce the negative effects of involuntary relocation.

Decisionmaking in Hospital Earthquake Evacuation: Does Distance From the Epicenter Matter?

STUDY OBJECTIVE

Over large expanses, the risk for hospital damage from an earthquake attenuates as the distance from the epicenter increases, which may not be true within the immediate disaster zone (near field), however. The following study examines the impact of epicenter distance and ground motion on hospital evacuation and closure for those structures near the epicenter of the 1994 Northridge Earthquake and the implications for patient evacuation.

METHODS

This is a retrospective case-control study of all hospitals reporting off-site evacuations or permanent closure because of damage from the January 17, 1994, earthquake in Northridge, CA. Control hospitals were randomly identified from those facilities that did not evacuate patients. Distances from the epicenter and peak ground accelerations were calculated for each hospital from Trinet ShakeMap data and compared.

RESULTS

Eight hospitals evacuated patients (study group); 4 of these hospitals were condemned. These were compared to 8 hospitals that did not evacuate patients (control group). The median epicenter-to-hospital distance for evacuated facilities was 8.1 miles (interquartile range [IQRs] 4.0 to 17.2 miles), whereas that for nonevacuated facilities was 14.1 miles (IRQ 10.5 to 17.0 miles). The difference in the median distances was 6.0 miles (95% confidence interval -4.8 to 11.9 miles). The peak ground acceleration had a median of 0.77 g (IQR 0.53 to 0.85 g) for study hospitals and a median of 0.36 g (IQR 0.24 to 0.50 g) for control hospitals, where 1 g equals the force of gravity. The difference in median acceleration of 0.41 g (95% CI 0.14 to 0.55 g) was significant (P=.009).

CONCLUSION

The distances from the epicenter for evacuated or condemned facilities and control hospitals do not appear to differ in the near field. Peak ground acceleration is a superior indicator of the risk for hospital damage and evacuation. Physicians can obtain these data in real time from the Internet and should transfer patients to facilities in areas of lower recorded peak ground acceleration regardless of distance from the epicenter.

Lessons from Hurricane Rita: the University of Texas Medical Branch Hospital's evacuation

In September 2005, the University of Texas Medical Branch at Galveston (UTMB) was threatened by Hurricane Rita, a category five storm. Abandoning its historic practice of clearing the hospital of all but the sickest patients, UTMB rapidly organized and conducted the first total evacuation in its 114-year history. The authors report how this was accomplished and lessons learned. Specific factors were crucial for success, including identifying an incident commander with sole authority to make decisions, developing and communicating a set of guiding principles, setting patient safety as our top priority, establishing an incident command center that consolidated vital institutional functions, avoiding delays in deciding to evacuate, identifying strategic partners, selecting essential personnel who would not be distracted by personal concerns during the emergency, and conducting periodic trial runs of emergency preparedness. Complex demands for communication were not met as well as was hoped. Technical problems were encountered with some communication devices that proved inoperable; trial runs would have probably revealed these problems in advance. Also, in-transit communication could be improved-not always knowing which patients were where, what vehicles were mired in stalled traffic, and what relocations occurred impeded optimal communication with patients' family members. Finally, a system ensuring that the recipients of UTMB's electronic records had the proper software to receive them would have facilitated communication and helped record keeping. The authors encourage physicians, as essential members of the health care team, to become better prepared to respond to disasters.

What Do We Really Know About the Transition to Adult-Centered Health Care? A Focus on Cerebral Palsy and Spina Bifida

OBJECTIVES

To address the lack of synthesis regarding the factors, processes, and outcomes specific to the transition from child-centered to adult-centered health care for people with cerebral palsy (CP) and spina bifida (SB); more specifically, to identify barriers, to outline key elements, to review empirical studies, and to make clinical and research recommendations.

DATA SOURCES

We searched Medline and CINAHL databases from 1990 to 2006 using the key words: transition, health care transition, pediatric health care, adult health care, health care access, health care use, chronic illness, special health care needs, and physical disability. The resulting studies were reviewed with a specific focus on clinical transition for persons with CP and SB, and were supplemented with key information from other diagnostic groups.

STUDY SELECTION

All studies meeting the inclusion criteria were included.

DATA EXTRACTION

Each article classified according to 5 criteria: methodology, diagnostic group, country of study, age group, and sample size.

DATA SYNTHESIS

We identified 149 articles: 54 discussion, 21 case series, 28 database or register, 25 qualitative, and 34 survey articles (some included multiple methods). We identified 5 key elements that support a positive transition to adult-centered health care: preparation, flexible timing, care coordination, transition clinic visits, and interested adult-centered health care providers. There was, however, limited empirical evidence to support the impact of these elements.

CONCLUSIONS

This review summarizes key factors that must be considered to support this critical clinical transition and sets the foundation for future research. It is time to apply prospective study designs to evaluate transition interventions and determine long-term health outcomes.

Reforming the acute phase of the inpatient journey

The medical admissions unit (MAU) of the Royal Free Hospital, London, should receive all acute accident and emergency (A&E) medical admissions. The unit aims to discharge 60% of patients and to transfer the remainder to a base ward within 48 hours of admission. This study tracked the patient journey from admission to A&E through the MAU during two parallel weeks, one year apart. Key bottlenecks were identified in the first audit and reforms implemented prior to the second. These reforms included improved transfer to base wards, improved weekend work patterns and improved access to investigation, specialist teams and pharmacy. The reforms served to facilitate the patient journey. A greater proportion of acute medical admissions were managed on the MAU and the number of patients exceeding a 48-hour stay fell from 55% to 10%. Both study periods demonstrated a peak in transfer activity from A&E in the 20 minutes before the four-hour target.

Case managers optimize patient safety by facilitating effective care transitions

In this new era of patient safety, the case manager, as an advocate and facilitator of care, has a pivotal role on the front line of healthcare delivery. Effective communication and collaboration between disciplines is key to the promotion of patient safety, and ultimately the avoidance of life-threatening medical errors. Across the healthcare continuum and within hospitals in particular, patients are routinely transferred from one service to another, from one level of care to another, or from one provider to another. As patients are stabilized and transitioned through the hospital system, there are multiple hand-offs of care or care transitions that can often expose the patient to fragmented service and increase the risk of communication breakdown. Ineffective hand-offs can result in a disruption of continuity between one level of care and the next. In a culture that places a strong emphasis on patient safety, case managers can facilitate opportunities that ease care transitions whereby a change in venue is no longer perceived as a disruption in the flow of care but rather is viewed as a coordinated changeover where cautious and comprehensive communication sets the tone for the continued delivery of safe and effective healthcare.

Expedited transfer for primary percutaneous coronary intervention: a program evaluation

BACKGROUND

A shorter time from symptom onset to reperfusion is associated with improved outcomes for patients with ST-segment elevation myocardial infarction (MI). Primary percutaneous coronary intervention is a favourable method of reperfusion if performed effectively and expeditiously. We sought to evaluate the impact of an expedited pre-hospital diagnosis and transfer pathway developed by a multidisciplinary team on the door-to-balloon time in a large urban community.

METHODS

We included all patients with ST-segment elevation MI who presented within 12 hours after symptom onset and who sought medical attention through Emergency Medical Services within the boundaries of the city of Calgary in the 16 months following the introduction of the pathway in June 2004. The primary aim was to determine the proportion of patients who received percutaneous coronary intervention within the recommended door-to-balloon time of 90 minutes.

RESULTS

The 358 patients (268 men) in the study cohort had a mean age of 63.2 (standard deviation 12.7) years; 140 (39.1%) had an anterior MI; and 23 (6.4%) had cardiogenic shock. The introduction of the pathway resulted in a median door-to-balloon time of 62 (interquartile range 45-84) minutes. A door-to-balloon time within 60 minutes and within the currently recommended 90 minutes was achieved in 48.9% and 78.8% of the patients respectively. The in-hospital and 30-day mortality rates were both 3.1%.

INTERPRETATION

In a community with multiple regional hospitals and a single facility for percutaneous coronary intervention, the implementation of a multidisciplinary pre-hospital diagnosis and transfer pathway was feasible and resulted in most patients in the study cohort receiving primary percutaneous coronary intervention within the recommended door-to-balloon time of 90 minutes.

Emergency Department Physician Activation of the Catheterization Laboratory and Immediate Transfer to an Immediately Available Catheterization Laboratory Reduce Door-to-Balloon Time in ST-Elevation Myocardial Infarction

Background— Consensus guidelines and hospital quality-of-care programs recommend that ST-elevation myocardial infarction patients achieve a door-to-balloon time of ≤90 minutes. However, there are limited prospective data on specific measures to significantly reduce door-to-balloon time.

Methods and Results— We prospectively determined the impact on median door-to-balloon time of a protocol mandating (1) emergency department physician activation of the catheterization laboratory and (2) immediate transfer of the patient to an immediately available catheterization laboratory by an in-house transfer team consisting of an emergency department nurse, a critical care unit nurse, and a chest pain unit nurse. We collected door-to-balloon time for 60 consecutive ST-elevation myocardial infarction patients undergoing emergency percutaneous intervention within 24 hours of presentation from October 1, 2004, through August 31, 2005, and compared this group with 86 consecutive ST-elevation myocardial infarction patients from September 1, 2005, through June 26, 2006, after protocol implementation. Median door-to-balloon time decreased overall (113.5 versus 75.5 minutes; P <0.0001), during regular hours (83.5 versus 64.5 minutes; P =0.005), during off-hours (123.5 versus 77.5 minutes; P <0.0001), and with transfer from an outside affiliated emergency department (147 versus 85 minutes; P =0.0006). Treatment within 90 minutes increased from 28% to 71% ( P <0.0001). Mean infarct size decreased (peak creatinine kinase, 2623±3329 versus 1517±1556 IU/L; P =0.0089), as did hospital length of stay (5±7 versus 3±2 days; P =0.0097) and total hospital costs per admission ($26 826±29 497 versus $18 280±8943; P =0.0125).

Conclusions— Emergency department physician activation of the catheterization laboratory and immediate transfer of the patient to an immediately available catheterization laboratory reduce door-to-balloon time, leading to a reduction in myocardial infarct size, hospital length of stay, and total hospital costs.

Effect of interhospital transfer on resource utilization and outcomes at a tertiary care referral center

OBJECTIVE

Mortality and length of stay are two outcome variables commonly used as benchmarks in rating the performance of medical centers. Acceptance of transfer patients has been shown to affect both outcomes and the costs of health care. Our objective was to compare observed and predicted lengths of stay, observed and predicted mortality, and resource consumption between patients directly admitted and those transferred to the intensive care unit (ICU) of a large academic medical center.

DESIGN

Observational cohort study.

SETTING

Mixed medical/surgical ICU of a university hospital.

PATIENTS

A total of 4,569 consecutive patients admitted to a tertiary care ICU from April 1, 1997, to March 30, 2000.

INTERVENTIONS

None.

MEASUREMENTS

Acute Physiology and Chronic Health Evaluation (APACHE) III score, actual and predicted ICU and hospital lengths of stay, actual and predicted ICU and hospital mortality, and costs per admission.

MAIN RESULTS

Crude comparison of directly admitted and transfer patients revealed that transfer patients had significantly higher APACHE III scores (mean, 60.5 vs. 49.7, p < .001), ICU mortality (14% vs. 8%, p < .001), and hospital mortality (22% vs. 14%, p < .001). Transfer patients also had longer ICU lengths of stay (mean, 6.0 vs. 3.8 days, p < .001) and hospital lengths of stay (mean, 20 vs. 15.9 days, p < .001). Stratified by disease severity using the APACHE III model, there was no difference in either ICU or hospital mortality between the two populations. However, in the transfer group with the lowest predicted mortality of 0-20%, ICU and hospital lengths of stay were significantly higher. In crude cost analysis, transfer patients' costs were $9,600 higher per ICU admission compared with nontransfer patients (95% confidence interval, $6,000-$13,400). Risk stratification revealed that the higher per-patient cost was entirely confined to the transfer patients with the lowest predicted mortality.

CONCLUSIONS

Patients transferred to a tertiary care ICU are generally more severely ill and consume more resources. However, they have similar adjusted mortality outcomes when compared with directly admitted patients. The difference in resource consumption is mainly attributable to the group of patients in the lowest predicted risk bracket.

Organizational Relationships Between Nursing Homes and Hospitals and Quality of Care During Hospital–Nursing Home Patient Transfers

OBJECTIVES

To identify organizational factors and hospital and nursing home organizational relationships associated with more-effective processes of care during hospital-nursing home patient transfer.

DESIGN

Mailed survey.

SETTING

Medicare- or Medicaid-certified nursing homes in New York State.

PARTICIPANTS

Nursing home administrators, with input from other nursing home staff.

MEASUREMENTS

Key predictor variables were travel time between the hospital and the nursing home, affiliation with the same health system, same corporate owner, trainees from the same institution, pharmacy or laboratory agreements, continuous physician care, number of beds in the hospital, teaching status, and frequency of geriatrics specialty care in the hospital. Key dependent variables were hospital-to-nursing home communication, continuous adherence to healthcare goals, and patient and family satisfaction with hospital care.

RESULTS

Of 647 questionnaires sent, 229 were returned (35.4%). There was no relationship between hospital-nursing home interorganizational relationships and communication, healthcare goal adherence, and satisfaction measures. Geriatrics specialty care in the hospital (r=0.157; P=.04) and fewer hospital beds (r=-0.194; P=.01) were each associated with nursing homes more often receiving all information needed to care for patients transferred from the hospital. Teaching status (r=0.230; P=.001) and geriatrics specialty care (r=0.185; P=.01) were associated with hospital care more often consistent with healthcare goals established in the nursing home.

CONCLUSION

No management-level organizational relationship between nursing home and hospital was associated with better hospital-to-nursing home transfer process of care. Geriatrics specialty care and characteristics of the hospital were associated with better hospital-to-nursing home transfer processes.

Transfer of patients--from the spoke to the hub

We describe the nature, frequency, and characteristics of transfers to a regional centre. This was a three month prospective descriptive study of all transfers into the hospital through the ED and a further sample survey of 100 patients received into the resuscitation room over a 2 year period. 105 patient transfers were surveyed over the three month period. A significant number (43 patients) arrived at the ED without prior notification being received by ED staff, a proportion (7 patients) warranting resuscitation room assessment. The rate of Doctor Transfer was 22%. Of the 23 patients that warranted assessment in the resuscitation room 10 were unaccompanied by a Doctor and 5 were unaccompanied by either a Doctor or a Nurse. 11% of transfers had no transfer letter or radiographs. Only 51% of transferred patients had an IV line in situ. 4 out of the 8 transfers into the resuscitation room performed by interns were associated with adverse events. There continues to be problems with the quality of care that these patients receive. Clinicians must be actively involved in the development of regional transfer protocols and interfacility agreements to ensure the safe transfer of patients to definitive care.

Impact of delayed transfer of critically ill patients from the emergency department to the intensive care unit*

OBJECTIVE

Numerous factors can cause delays in transfer to an intensive care unit for critically ill emergency department patients. The impact of delays is unknown. We aimed to determine the association between emergency department "boarding" (holding admitted patients in the emergency department pending intensive care unit transfer) and outcomes for critically ill patients.

DESIGN

This was a cross-sectional analytical study using the Project IMPACT database (a multicenter U.S. database of intensive care unit patients). Patients admitted from the emergency department to the intensive care unit (2000-2003) were included and divided into two groups: emergency department boarding >or=6 hrs (delayed) vs. emergency department boarding <6 hrs (nondelayed). Demographics, intensive care unit procedures, length of stay, and mortality were analyzed. Groups were compared using chi-square, Mann-Whitney, and unpaired Student's t-tests.

SETTING

Emergency department and intensive care unit.

PATIENTS

Patients admitted from the emergency department to the intensive care unit (2000-2003).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Main outcomes were intensive care unit and hospital survival and intensive care unit and hospital length of stay. During the study period, 50,322 patients were admitted. Both groups (delayed, n = 1,036; nondelayed, n = 49,286) were similar in age, gender, and do-not-resuscitate status, along with Acute Physiology and Chronic Health Evaluation II score in the subgroup for which it was recorded. Among hospital survivors, the median hospital length of stay was 7.0 (delayed) vs. 6.0 days (nondelayed) (p < .001). Intensive care unit mortality was 10.7% (delayed) vs. 8.4% (nondelayed) (p < .01). In-hospital mortality was 17.4% (delayed) vs. 12.9% (nondelayed) (p < .001). In the stepwise logistic model, delayed admission, advancing age, higher Acute Physiology and Chronic Health Evaluation II score, male gender, and diagnostic categories of trauma, intracerebral hemorrhage, and neurologic disease were associated with lower hospital survival (odds ratio for delayed admission, 0.709; 95% confidence interval, 0.561-0.895).

CONCLUSIONS

Critically ill emergency department patients with a >or=6-hr delay in intensive care unit transfer had increased hospital length of stay and higher intensive care unit and hospital mortality. This suggests the need to identify factors associated with delayed transfer as well as specific determinants of adverse outcomes.