Comparing the Effect of Throughput and Output Factors on Emergency Department Crowding: A Retrospective Observational Cohort Study.

STUDY OBJECTIVE: This study compares how throughput and output factors affect emergency department (ED) median waiting room time. METHODS: Administrative health care use records were used to identify all daytime (8 am to 8 pm) visits made to adult EDs in Winnipeg, Canada, between April 1, 2012, and March 31, 2013. First, we measured the waiting room time (from patient registration until transfer into the ED) of each index visit (incoming patient). We then linked each index visit to a group of existing patients surrounding it and counted the number of existing patients engaged in throughput processes (radiographs, computed tomography [CT] scans, advanced diagnostic tests) and one output process (waiting to be hospitalized). Regression analysis was used to measure how strongly each factor uniquely affected incoming patient median waiting room time, stratified by the acuity level. RESULTS: Analyses were performed on 143,172 index visits. On average, 153.4 radiographs and 48.5 CT scans were conducted daily, whereas 45.3 patients were admitted daily to hospital. Median waiting room time was shortest (8.0 minutes) for the highest-acuity index visits and was not influenced by these throughput or output factors. For all other index visits, median waiting room time was associated strongly with the number of existing patients receiving radiographs, and, to a lesser extent, with the number of existing patients receiving CT scans and waiting for hospital admission. CONCLUSION: Both throughput and output factors affect how long newly arriving ED patients remain in the waiting room. This suggests that a range of strategies may help to reduce ED wait time, each requiring stronger ED and hospital partnerships.

Patterns of emergency department utilization by patients on chronic dialysis: A population-based study.

IMPORTANCE: Patients on dialysis are often elderly and frail, with multiple comorbid conditions, and are heavy users of Emergency Department (ED) services. However, objective data on the frequency and pattern of ED utilization by dialysis patients are sparse. Such data could identify periods of highest risk for ED visits and inform health systems interventions to mitigate these risks and improve outcomes. OBJECTIVE: To describe the pattern and frequency of presentation to ER by dialysis patients. DESIGN: Retrospective cohort study using administrative data collected over ten years (2000-2009) in the Province of Manitoba, Canada. SETTING: Patients presenting to any of 9 ED's in Winnipeg and Brandon Manitoba. These departments serve >90% of the population of Manitoba, Canada (population 1.2 million). PARTICIPANTS: All patients presenting to an ED in any of 9 emergency departments in Manitoba, Canada. EXPOSURE: Dialysis status. MAIN OUTCOMES: Presentation to the ED. RESULTS: Over 2.1 million ED visits by more than 1.2 million non-dialysis patients and 17,782 ED visits by 3257 dialysis patients were included. Dialysis patients presented 8.5 times more frequently to the ED than the general population (age and sex adjusted, p<0.001). For dialysis patients, ED utilization was significantly higher following the long interdialytic interval (33.6% higher Mondays and 19.5% higher Tuesdays vs. other days of the week, p<0.001) and was 10-fold higher in the 7 days before and after the initiation of dialysis. CONCLUSION AND RELEVANCE: The heavy use of ED services by dialysis patients spikes upward following the long interdialytic interval and also in the week before and after dialysis initiation. The relative risks associated with these vulnerable periods were much higher than those reported for clinical patient characteristics. We propose that intrinsic gaps in the structure of care delivery (e.g. 3 times a week dialysis, imperfect surveillance and clinical monitoring of patients with low GFR) may be the fundamental drivers of this periodicity. Strategies to mitigate this excess health risk are needed.

An ED paradox: patients who arrive by ambulance and then leave without consulting an ED provider.

BACKGROUND: Scientists have called for strategies to identify ED patients with unmet needs. We identify the unique profile of ED patients who arrive by ambulance and subsequently leave without consulting a provider (ie, a paradoxical visit, PV). METHODS: Using a retrospective cohort design, administrative data from Winnipeg, Manitoba were interrogated to identify all ED patients 17+ years old as having zero, single or multiple PVs in 2012/2013. Analyses compare the sociodemographic, physical (eg, arthritis), mental (eg, substance abuse) and concurrent healthcare use profile of non-PV, single and multiple PV patients. RESULTS: The study cohort consisted of 122 639 patients with 250 754 ED visits. Across all ED sites, 2.3% of patients (N=2815) made 3387 PVs, comprising 1.4% of all ED visits. Descriptively, more single versus non-PV patients lived in urban core and lowest-income areas, were frequent ED users generally, were substance abusers and had seven plus primary care physician visits. Multiple PV patients had a similar but more extreme profile versus their single PV counterparts (eg, 54.7% of multiple vs 27.4% of single PV patients had substance abuse challenges). From multivariate statistics, single versus non-PV patients are defined uniquely by their frequent ED use, by their substance abuse, as living in a core and low income area, and as having multiple visits with primary care physicians. CONCLUSIONS: PV patients have needs that do not align with the acute model of ED care. These patients may benefit from a more integrated care approach likely involving allied health professionals.

A Microfluidic Platform for Evaluating Neutrophil Chemotaxis Induced by Sputum from COPD Patients.

Chronic Obstructive Pulmonary Disease (COPD) is a common lung disease characterized by breathing difficulty as a consequence of narrowed airways. Previous studies have shown that COPD is correlated with neutrophil infiltration into the airways through chemotactic migration. However, whether neutrophil chemotaxis can be used to characterize and diagnose COPD is not well established. In the present study, we developed a microfluidic platform for evaluating neutrophil chemotaxis to sputum samples from COPD patients. Our results show increased neutrophil chemotaxis to COPD sputum compared to control sputum from healthy individuals. The level of COPD sputum induced neutrophil chemotaxis was correlated with the patient's spirometry data. The cell morphology of neutrophils in a COPD sputum gradient is similar to the morphology displayed by neutrophils exposed to an IL-8 gradient, but not a fMLP gradient. In competing gradients of COPD sputum and fMLP, neutrophils chemotaxis and cell morphology are dominated by fMLP.