Frequent Fliers, Internal and External Validity, and Problems With Making Continuous Variables Binary: Answers to the May 2009 Journal Club Questions

 Section editors: Tyler W. Barrett, MD; David L. Schriger, MD, MPH

 Editor's Note: You are reading answers to the ninth installment of Annals of Emergency Medicine Journal Club. The questions and the article they are about (Aisiku et al. Ann Emerg Med. 2009;53:587-593.) were published in the May 2009 issue.Information about journal club can be found at http://www.annemergmed.com/content/journalclub.Readers should recognize that these are suggested answers. We hope they are accurate; we know that they are not 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” () so that individuals planning a journal club can assign the right question to the right student. The “novice” rating does not imply that a novice should be able to spontaneously answer the question. “Novice” means we expect that someone with little background should be able to do a bit of reading, formulate an answer, and teach the material to others. Intermediate and advanced questions also will likely require some reading and research, and that reading will be sufficiently difficult that some background in clinical epidemiology will be helpful in understanding the reading and concepts.We are interested in receiving feedback about this feature. Please e-mail journalclub@acep.org with your comments.

PII: S0196-0644(09)00404-1

doi: 10.1016/j.annemergmed.2009.04.013