Health policy and clinical practice/original research
The Impact of Emergency Department Crowding Measures on Time to Antibiotics for Patients With Community-Acquired Pneumonia

Presented at the Society for Academic Emergency Medicine Annual Meeting, May 2007, Chicago, IL.
https://doi.org/10.1016/j.annemergmed.2007.07.021Get rights and content

Study objective

We seek to determine the impact of emergency department (ED) crowding on delays in antibiotic administration for patients with community-acquired pneumonia.

Methods

We performed a retrospective cohort study of adult patients admitted with community-acquired pneumonia from January 1, 2003, to April 31, 2005, at a single, urban academic ED. The main outcome was a delay (>4 hours from arrival) or nonreceipt of antibiotics in the ED. Eight ED crowding measures were assigned at triage. Multivariable regression and bootstrapping were used to test the adjusted impact of ED crowding measures of delayed (or no) antibiotics. Predicted probabilities were then calculated to assess the magnitude of the impact of ED crowding on the probability of delayed (or no) antibiotics.

Results

In 694 patients, 44% (95% confidence interval [CI] 40% to 48%) received antibiotics within 4 hours and 92% (95% CI 90% to 94%) received antibiotics in the ED. Increasing levels of ED crowding were associated with delayed (or no) antibiotics, including waiting room number (odds ratio [OR] 1.05 for each additional waiting room patient [95% CI 1.01 to 1.10]) and recent ED length of stay for admitted patients (OR 1.14 for each additional hour [95% CI 1.04 to 1.25]). When the waiting room and recent length of stay were both at the lowest quartiles (ie, not crowded), the predicted probability of delayed (or no) antibiotics within 4 hours was 31% (95% CI 21% to 42%); when both were at the highest quartiles, the predicted probability was 72% (95% CI 61% to 81%).

Conclusion

ED crowding is associated with delayed and nonreceipt of antibiotics in the ED for patients admitted with community-acquired pneumonia.

Introduction

Emergency department (ED) crowding is a public health crisis in the United States.1, 2, 3, 4 Factors that contribute to ED crowding include high patient volume, ED and hospital closures, high levels of hospital occupancy, and poor access to primary care.5, 6, 7, 8, 9, 10, 11, 12, 13, 14 ED patients are also increasingly older, more severely ill, and frequently experience long ED stays for diagnostic testing, treatment, and waiting for available hospital beds.15, 16 The nursing shortage compounds the problem and many EDs have trouble maintaining adequate staffing levels.17 As a result, ED crowding is the functional state of high service demand coupled with a limited supply of space and personnel.

The association between ED crowding and poorer-quality emergency care has been difficult to establish. A recent study reported that 4 proposed measures of ED crowding are weak predictors of subjective ED quality.18 The Joint Commission and the Centers for Medicare & Medicaid Services have proposed 2 time-sensitive indicators of ED quality: (1) antibiotic administration within 4 hours of arrival for admitted patients with community-acquired pneumonia (the measure is named PN-5b) and 2) percutaneous intervention within 2 hours for patients with acute myocardial infarction (the measure is named AMI-3a).19 Although the use of these measures to define ED quality has been controversial, both measures are associated with improved patient care outcomes.20, 21, 22, 23 Our group recently studied the impact of measures of ED crowding on yearly performance data on AMI-3a and PN-5b in 24 academic centers.24 We found that ED crowding measures predicted poorer performance on time-sensitive community-acquired pneumonia care (PN-5b) but not time-sensitive acute myocardial infarction care (AMI-3a). However, the analysis was at performed at the hospital level, and conclusions are limited by the ecologic nature of the study design, in that we could not demonstrate that individual patients with delayed treatment were actually treated during times of crowding.25

Our primary aim was to more directly test whether available measures of ED crowding, including measures of both input and output, were positively associated with delays in time to antibiotics for individual patients with community-acquired pneumonia managed in a large academic ED. We hypothesized that common measures of ED crowding would be predictive of a higher likelihood of failure to deliver antibiotics in the ED or within 4 hours.

Section snippets

Study Design and Setting

We performed a retrospective cohort study of all adult patients 18 years and older who were admitted with an ED diagnosis of community-acquired pneumonia from January 1, 2003, to April 31, 2005. The study was performed in a large, urban, tertiary-care ED with an emergency medicine residency program. The ED has 25 individual patient rooms and 15 additional hallway treatment areas. During the study period, annual ED visits ranged from approximately 55,000 to 57,000 per year.

Data Collection and Processing

We identified all

Results

Over the study period, a total of 702 patients were identified according to principal discharge diagnosis of community-acquired pneumonia who were admitted to the hospital, and 694 patients met inclusion criteria. There were 32 ED attending physicians who admitted this group of community-acquired pneumonia patients. The median number of patients per physician was 16 (IQR 10 to 29). Forty-four percent (95% CI 40% to 48%) received antibiotics in 4 hours or less, and 92% (95% CI 90% to 94%) of all

Limitations

A primary limitation of this study is that it was performed at only 1 hospital, affecting the generalizability of this association. In addition, during the study period, the proportion of patients with pneumonia who received antibiotics in this ED was considerably lower than national benchmarks.30 There exists the possibility that unmeasured confounding that we did not account for in this analysis explains this association. Also, because nurses manually enter time of administration after

Discussion

We demonstrate an association between ED crowding and the delivery of antibiotics within 4 hours of arrival to patients admitted with pneumonia in a large, academic ED. This relationship makes sense: when an ED is busier, delivery of a complex and time-sensitive intervention that involves multiple steps such as the diagnosis of community-acquired pneumonia and delivery of antibiotics will be less efficient.29 This confirms previous work in which we reported an association at the hospital level

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    Supervising editor: Donald M. Yealy, MD

    Author contributions: JMP, ARL, and JPM conceived and designed the study. HL and CP handled data management and performed critical review. JMP, ARL, JPM performed the statistical analysis. WBG and JEH helped supervise the study, performed critical review, and provided insight into the study design. JMP drafted the article, which was reviewed by all of the authors. JMP takes responsibility for the paper as a whole.

    Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article, that might create any potential conflict of interest. The authors have stated that no such relationships exist. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement. Jesse M. Pines, MD, MBA, is supported by the Riggs Family/Health Policy Grant from the American College of Emergency Physicians.

    Reprints not available from the authors.

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