Planning model of resource utilization in an academic pediatric emergency department

A Review on the Contribution of Emergency Department Simulation Studies in Reducing Wait Time

Background: Because of the important role of hospital emergency departments (EDs) in providing urgent care, EDs face a constantly large demand that often results in long wait times. Objective: To review and analyze the existing literature in ED simulation modeling and its contribution in reducing patient wait time. Methods: A literature review was conducted on simulation modeling in EDs. Results: A total of 41 articles have met the inclusion criteria. The papers were categorized based on their motivations, modeling techniques, data collection processes, patient classification, recommendations, and implementation statuses. Real impact is seldom measured; only four papers (~10%) have reported the implementation of their recommended changes in the real world. Conclusion: The reported implementations contributed significantly to wait time reduction, but the proportion of simulation studies that are implemented is too low to conclude causality. Researchers should budget resources to implement their simulation recommendations in order to measure their impact on patient wait time.

Adding more junior residents may worsen emergency department crowding

BACKGROUND

Although increasing staff numbers during shifts when emergency department (ED) crowding is severe can help meet patient demand, it remains unclear how different types of added staff, particularly junior residents, may affect crowding.

METHODS

To identify associations between types of staff and ED crowding, we conducted a cross-sectional, single-center study in the ED of a large, teaching hospital in Japan between January and December 2012. Patients who visited the ED during the study period were enrolled. We excluded (1) patients previously scheduled to visit the ED, and (2) neonates transferred from other hospitals. During the study period, 27,970 patients were enrolled. Types of staff analyzed were junior (first and second year) residents, senior (third to fifth year) residents, attending (board-certified) physicians, and nurses. A generalized linear model was applied to length of ED stay for all patients as well as admitted and discharged patients to quantify an association with the additional staff.

RESULTS

In the model, addition of one attending physician or senior resident was associated with decreased length of ED stay for total patients by 3.88 or 1.64 minutes, respectively (95% CI, 2.20-5.56 and 0.81-2.48 minutes); while additional nursing staff had no association. Surprisingly, however, one additional junior resident was associated with prolonged length of ED stay for total patients by 0.97 minutes (95% CI 0.37-1.57 minutes) and for discharged patients by 1.01 minutes (95% CI 0.45-1.59 minutes).

CONCLUSION

Staffing adjustments aimed at alleviating ED crowding should focus on adding more senior staff during peak-volume shifts.

Execution of diagnostic testing has a stronger effect on emergency department crowding than other common factors: a cross-sectional study

STUDY OBJECTIVE

We compared the effects of execution of diagnostic tests in the emergency department (ED) and other common factors on the length of ED stay to identify those with the greatest impacts on ED crowding.

METHODS

Between February 2010 and January 2012, we conducted a cross-sectional, single-center study in the ED of a large, urban, teaching hospital in Japan. Patients who visited the ED during the study period were enrolled. We excluded (1) patients scheduled for admission or pharmaceutical prescription, and (2) neonates requiring intensive care transferred from other hospitals. Multivariate linear regression was performed on log-transformed length of ED stay in admitted and discharged patients to compare influence of diagnostic tests and other common predictors. To quantify the range of change in length of ED stay given a unit change of the predictor, a generalized linear model was used for each group.

RESULTS

During the study period, 55,285 patients were enrolled. In discharged patients, laboratory blood tests had the highest standardized β coefficient (0.44) among common predictors, and increased length of ED stay by 72.5 minutes (95% CI, 72.8-76.1 minutes). In admitted patients, computed tomography (CT) had the highest standardized β coefficient (0.17), and increased length of ED stay by 32.7 minutes (95% CI, 40.0-49.9 minutes). Although other common input and output factors were significant contributors, they had smaller standardized β coefficients in both groups.

CONCLUSIONS

Execution of laboratory blood tests and CT had a stronger influence on length of ED stay than other common input and output factors.

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.

Forecasting emergency department crowding: a prospective, real-time evaluation

OBJECTIVE

Emergency department crowding threatens quality and access to health care, and a method of accurately forecasting near-future crowding should enable novel ways to alleviate the problem. The authors sought to implement and validate the previously developed ForecastED discrete event simulation for real-time forecasting of emergency department crowding.

DESIGN AND MEASUREMENTS

The authors conducted a prospective observational study during a three-month period (5/1/07-8/1/07) in the adult emergency department of a tertiary care medical center. The authors connected the forecasting tool to existing information systems to obtain real-time forecasts of operational data, updated every 10 minutes. The outcome measures included the emergency department waiting count, waiting time, occupancy level, length of stay, boarding count, boarding time, and ambulance diversion; each forecast 2, 4, 6, and 8 hours into the future.

RESULTS

The authors obtained crowding forecasts at 13,239 10-minute intervals, out of 13,248 possible (99.9%). The R(2) values for predicting operational data 8 hours into the future, with 95% confidence intervals, were 0.27 (0.26, 0.29) for waiting count, 0.11 (0.10, 0.12) for waiting time, 0.57 (0.55, 0.58) for occupancy level, 0.69 (0.68, 0.70) for length of stay, 0.61 (0.59, 0.62) for boarding count, and 0.53 (0.51, 0.54) for boarding time. The area under the receiver operating characteristic curve for predicting ambulance diversion 8 hours into the future, with 95% confidence intervals, was 0.85 (0.84, 0.86).

CONCLUSIONS

The ForecastED tool provides accurate forecasts of several input, throughput, and output measures of crowding up to 8 hours into the future. The real-time deployment of the system should be feasible at other emergency departments that have six patient-level variables available through information systems.

Advanced medical simulation applications for emergency medicine microsystems evaluation and training

Participants in the 2008 Academic Emergency Medicine Consensus Conference "The Science of Simulation in Healthcare: Defining and Developing Clinical Expertise" morning workshop session on developing systems expertise were tasked with evaluating best applications of simulation techniques and technologies to small-scale systems in emergency medicine (EM). We collaborated to achieve several objectives: 1) describe relevant theories and terminology for discussion of health care systems and medical simulation, 2) review prior and ongoing efforts employing systems thinking and simulation programs in general medical sectors and acute care medicine, 3) develop a framework for discussion of systems thinking for EM, and 4) explore the rational application of advanced medical simulation methods to a defined framework of EM microsystems (EMMs) to promote a "quality-by-design" approach. This article details the materials compiled and questions raised during the consensus process, and the resulting simulation application framework, with proposed solutions as well as their limitations for EM systems education and improvement.

Systematic review of emergency department crowding: causes, effects, and solutions

Emergency department (ED) crowding represents an international crisis that may affect the quality and access of health care. We conducted a comprehensive PubMed search to identify articles that (1) studied causes, effects, or solutions of ED crowding; (2) described data collection and analysis methodology; (3) occurred in a general ED setting; and (4) focused on everyday crowding. Two independent reviewers identified the relevant articles by consensus. We applied a 5-level quality assessment tool to grade the methodology of each study. From 4,271 abstracts and 188 full-text articles, the reviewers identified 93 articles meeting the inclusion criteria. A total of 33 articles studied causes, 27 articles studied effects, and 40 articles studied solutions of ED crowding. Commonly studied causes of crowding included nonurgent visits, "frequent-flyer" patients, influenza season, inadequate staffing, inpatient boarding, and hospital bed shortages. Commonly studied effects of crowding included patient mortality, transport delays, treatment delays, ambulance diversion, patient elopement, and financial effect. Commonly studied solutions of crowding included additional personnel, observation units, hospital bed access, nonurgent referrals, ambulance diversion, destination control, crowding measures, and queuing theory. The results illustrated the complex, multifaceted characteristics of the ED crowding problem. Additional high-quality studies may provide valuable contributions toward better understanding and alleviating the daily crisis. This structured overview of the literature may help to identify future directions for the crowding research agenda.

Applying the variety reduction principle to management of ancillary services

BACKGROUND

As central diagnostic facilities, computer tomography (CT) scans appear to be bottlenecks in many patient-care processes. This study describes a case study concerning redesign of a CT scan department in the Academic Medical Center in Amsterdam, the Netherlands.

PURPOSES

The aim was to decrease access time for the CT-scan and simultaneously increase utilization level.

METHODOLOGY/APPROACH

An important cause of relatively low-capacity utilization is variability in the time needed for the scanning process. We performed a qualitative and quantitative analysis of current processes; identified bottlenecks and selected interventions with the greatest expected reduction of variability in flow time.

FINDINGS

The most promising and most feasible opportunity appeared to be to reallocate the insertion of intravenous access lines to a preparation room. The time needed for this activity was very hard to predict and needed a lot of slack in the lead time for appointments. By removing it from the CT room, lead time could be reduced by 5 minutes. The intervention resulted in a decrease of access time from 21 days to less than 5 days, and an increase of the utilization rate from 44% to 51%. This contributed directly to patient service and indirectly to cost reduction.

PRACTICE IMPLICATIONS

Our strategy is applicable in every appointment-based hospital facility with variation in the length of time of the process. It allows to simultaneously reduce costs and improve service for the patient.

Modeling an emergency medical services system using computer simulation

STUDY OBJECTIVES

In the emergency medical services (EMS) system, appropriate prehospital care can substantially decrease casualty mortality and morbidity. This study designed a simulation model, evaluated the existing EMS system, and suggested improvements.

METHODS

The study focused on 23 networked EMS hospitals affiliated with 36 emergency response units (subgroups) to perform two-tier rescues (advanced life support [ALS] in addition to basic life support [BLS] services) in Taipei, Taiwan. Using the existing EMS model as a base, this research constructed a computer simulation model and explored several model alternatives to achieve the study's objectives. The virtual models varied with staffing level, number of assigned emergency network hospitals, and various two-tier rescue probabilities.

RESULTS

Increasing the staffing to two teams for Hospital 22 lessened the call waiting probability (delay between rescue call and ambulance dispatch) by 50%, even if the dispatch rate of the two-tier rescue increased from the empirical 2% to a simulated 10 and 20%. Changing the two-tier rescue pattern so each EMS subgroup cooperated with two specific, preassigned network hospitals lowered the probability of patients having to wait for rescue dispatch to under 1%.

CONCLUSION

The following alternatives provided the greatest combination of effectiveness, quality patient care, and cost-efficiency: (1) because of its unique location, increase Hospital 22's staffing level to two ALS teams. (2) Establish a specific rescue protocol for the two-tier system that preassigns two network hospitals to each of the 36 EMS subgroups along with a prearranged calling sequence. If implemented, this will improve EMS performance, streamline the system, reduce randomness, and enhance efficiency.

Resource reallocation in an emergency medical service system using computer simulation

Emergency medical service (EMS) policy makers must seek to achieve maximum effectiveness with finite resources. This research establishes an EMS computer simulation model using eM-Plant software. The simulation model is based on Taipei city's EMS system with input data from prehospital care records from December 2000; it manipulates resource allocation levels and rates of idle errands. Presently, EMS ambulance utilization is about 8.78%. On average, 20.89 minutes are required to transport a patient to the hospital. Computer simulations showed that reducing the number of ambulances to one at each of the 36 response units increases the utilization rate to 15.47% but does not compromise the current service quality level. Thus, ambulance utilization improves, times of patients waiting for pre-hospital care and arrival at hospitals are only slightly affected, and considerable cost savings result. This study provides a research methodology and suggests specific policy directions for resource allocation in EMS. Limiting the number of ambulances to one per response unit reduces costs, increases efficiency, and yet maintains the same operational pattern of medical service.

Emergency medicine resident documentation: results of the 1999 american board of emergency medicine in-training examination survey

OBJECTIVES

To assess how emergency medicine (EM) residents perform medical record documentation, and how well they comply with Health Care Financing Administration (HCFA) Medicare charting guidelines. In addition, the study investigated their abilities and confidence with billing and coding of patient care visits and procedures performed in the emergency department (ED). Finally, the study assessed their exposure to both online faculty instruction and formal didactic experience with this component of their curriculum.

METHODS

A survey was conducted consisting of closed-ended questions investigating medical record documentation in the ED. The survey was distributed to all EM residents, EM-internal medicine, and EM-pediatrics residents taking the 1999 American Board of Emergency Medicine (ABEM) In-Training examination. Five EM residents and the Society for Academic Emergency Medicine (SAEM) board of directors prevalidated the survey. Summary statistics were calculated and resident levels were compared for each question using either chi-square or Fisher's exact test. Alpha was 0.05 for all comparisons.

RESULTS

Completed surveys were returned from 88.5% of the respondents. A small minority of the residents code their own charts (6%). Patient encounters are most frequently documented on free-form handwritten charts (38%), and a total of 76% of the respondents reported using handwritten forms as a portion of the patient's final chart. Twenty-nine percent reported delays of more than 30 minutes to access medical record information for a patient evaluated in their ED within the previous 72 hours. Twenty-five percent "never" record their supervising faculty's involvement in patient care, and another 25% record that information "1-25%" of the time. Seventy-nine percent are "never" or "rarely" requested by their faculty to clarify or add to medical records for billing purposes. Only 4% of the EM residents were "extremely confident" in their ability to perform billing and coding, and more than 80% reported not knowing the physician charges for services or procedures performed in the ED.

CONCLUSIONS

The handwritten chart is the most widely used method of patient care documentation, either entirely or as a component of a templated chart. Most EM residents do not document their faculty's participation in the care of patients. This could lead to overestimation of faculty noncompliance with HCFA billing guidelines. Emergency medicine residents are not confident in their knowledge of medical record documentation and coding procedures, nor of charges for services rendered in the ED.

Can sick children tell time?: emergency department presentation patterns of critically ill children

OBJECTIVE

Children show a consistent pattern of ED use, with the majority of patients presenting during the late afternoon and evening hours. This study evaluated whether such a diurnal pattern also exists for critically ill children and the implications of such a presentation pattern on ED staffing.

METHODS

A review was performed of the ED diagnoses and times of presentation for children less than 12 years of age at 28 nonpediatric hospitals over the six-year period from July 1990 to October 1996. In addition to total ED pediatric visits, a subset of critically ill children (CIC) were identified as those with an ED diagnosis of: meningitis, cardiac arrest, diabetic ketoacidosis, status epilepticus, meningococcemia, or epiglottitis, or those undergoing endotracheal intubation in the ED. A second group of non-critically ill children (NCIC) was composed of children with an ED diagnosis of otitis media, tonsillitis, or pharyngitis. Data collected on each patient included age, diagnosis, site of care, and time of service. Presentation patterns for all three groups were compared for time of day, with statistical analysis through chi-square, ANOVA, and Spearman's rho correlation.

RESULTS

A total of 409,820 pediatric ED visits were examined, with 688 CIC children and 28,344 NCIC identified. Presentation patterns for NCIC visits mirrored those of the total pediatric population, with the traditional increase in the late afternoon and evening hours (correlation 0.96). CIC presented much more erratically, with a distribution spread more uniformly throughout the day compared with the total pediatric population (correlation 0.72). Thirty-seven percent of CIC presented during the evening hours of 16:00 to 24:00, compared with 49% for NCIC and 53% for the total pediatric population, while 22% of CIC presented from 24:00 to 08:00 compared with only 13% of NCIC and 10% of total pediatric patients (p < 0.001).

CONCLUSION

Critically ill children present more uniformly throughout the day and do not have the same presentation patterns as ambulatory children. ED staffing should reflect this difference and not focus pediatric ED services simply on hours of peak pediatric visits.