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Are Smaller Emergency Departments More Prone to Volume Variability?

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Smaller emergency departments (EDs) experience high-volume days more frequently than larger ones. This study recommends using 10% above median daily volume to define high-volume days for better resource planning.

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Area of Science:

  • Emergency Medicine
  • Healthcare Operations Research
  • Health Services Research

Background:

  • Daily patient volumes in emergency departments (EDs) exhibit significant variability.
  • Existing definitions of
  • high-volume
  • days lack standardization.
  • The relationship between ED size and high-volume day frequency remains unclear.

Purpose of the Study:

  • To determine the correlation between emergency department (ED) size and the frequency of high-volume days.
  • To develop a standardized metric for identifying high-volume days in EDs.

Main Methods:

  • Analysis of retrospective patient arrival data from 32 EDs (1,682,374 visits) between July 2018 and June 2019.
  • Development of linear regression models to assess ED size and volume variability.
  • Application of regression analysis and Pearson correlation to evaluate median daily volumes against thresholds (5-20% above median).

Main Results:

  • A strong negative correlation was found between ED median daily volume and volume variability (R² = 81.0%, P < 0.0001).
  • Regression models for high-volume day thresholds (5-20% above median) showed significant predictive power (R² ranging from 49.4% to 71.8%, P < 0.0001).
  • Lower-volume EDs were found to experience high-volume days more frequently than higher-volume EDs.

Conclusions:

  • High-volume days occur more frequently in smaller EDs, potentially leading to unpredictable staffing and operational challenges.
  • A lack of a standard definition for high-volume days complicates resource allocation.
  • Recommends defining a high-volume day as 10% above the median daily volume for generalizability and simplicity.