Annals of Emergency Medicine
Volume 51, Issue 6 , Pages 782-789 , June 2008

Measures of Emergency Department Crowding, Odds Ratios, and the Dangers of Making Continuous Data Categorical: Answers to January 2008 Journal Club Questions

  • Tyler W. Barrett, MD

      Affiliations

    • Vanderbilt University Medical Center, Nashville, TN
    • ,
  • David L. Schriger, MD, MPH

      Affiliations

    • University of California, Los Angeles, Los Angeles, CA

References 

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  2. Ospina MB, Bond K, Schull M, et al. Key indicators of crowding in Canadian emergency departments: a Delphi study. Can J Emerg Med. 2007;9:339–346
  3. Hoot NR, Zhou C, Jones I, et al. Measuring and forecasting emergency department crowding in real time. Ann Emerg Med. 2007;49:747–755
  4. Pines JM, Localio AR, Hollander JE, et al. The impact of emergency department crowding measures on time to antibiotics for patients with community-acquired pneumonia. Ann Emerg Med. 2007;50:517–519
  5. Weiss SJ, Ernst AA, Nick TG. Comparison of the National Emergency Department Crowding Scale and the Emergency Department Work Index for quantifying emergency department crowding. Acad Emerg Med. 2006;13:513–518
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  7. McCarthy ML, Aronsky D, Jones ID, et al. The emergency department occupancy rate: a simple measure of emergency department crowding?. Ann Emerg Med. 2008;51:15–24
  8. Altman DG, Royston P. The cost of dichotomising continuous variables. BMJ. 2006;332:1216
  9. Greenland S, Rothman KJ. Measures of effect and association. In:  Rothman KJ,  Greenland S editor. Modern Epidemiology. 2nd ed.. Philadelphia, PA: Lippincott-Raven; 1998;p. 47–59
  10. Sistrom CL, Garvan CW. Proportions, odds, and risk. Radiology. 2004;230:12–19
  11. Newman TB, Browner WS, Cummings SR, et al. Designing cross-sectional and case-control studies. In:  Hulley SB,  Cummings SR,  Browner WS, et al. editor. Designing Clinical Research. 3rd ed.. Philadelphia, PA: Lippincott Williams & Wilkins; 2007;p. 124–125
  12. Rothman KJ, Greenland S. Modern Epidemiology. In: 2nd ed.. Philadelphia, PA: Lippincott-Raven; 1998;p. 373–374

 Editor's note: These questions and answers refer to the Pines and Hollander paper on the effect of emergency department crowding on analgesia administration [Ann Emerg Med. 2008; 51:1-5]. Readers should recognize that these are suggested answers and, although it is hoped that they are correct, are by no means comprehensive. There are many other points that could be made about these questions or about the article in general. Questions are rated “novice,” (), “intermediate,” (), and “advanced” (). Readers should also note that Drs. Pines and Hollander shared their data set with us so that we could better illustrate some of the points we make in the answers and, when we found a few inconsequential blemishes in their data set, granted us permission to use these blemishes as teaching points. We acknowledge their generosity and note that the kinds of errors we detected are likely to be found in any large clinical data set.

PII: S0196-0644(07)01947-6

doi: 10.1016/j.annemergmed.2007.12.024

Annals of Emergency Medicine
Volume 51, Issue 6 , Pages 782-789 , June 2008

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