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Volume 56, Issue 2 , Pages 188-200 , August 2010

Is the Golden Hour Tarnished? Registries and Multivariable Regression: Answers to the March 2010 Journal Club Questions

Linear regression of weight by height. A, Knowledge of length provides no information about the weight. B, There is a relationship between the 2 variables, and knowledge of height can improve predicti

Linear regression of weight by height. A, Knowledge of length provides no information about the weight. B, There is a relationship between the 2 variables, and knowledge of height can improve predictions about weight.
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The 4 panels show how more complex models can decrease the overall error between predictions and reality. The red bars indicate the error for each measurement, and the sum of the length of these bars

The 4 panels show how more complex models can decrease the overall error between predictions and reality. The red bars indicate the error for each measurement, and the sum of the length of these bars is signified by ∑ |error|. ∑ error² is calculated as the sum of the square of each of these red bars. A, The example is equivalent to guessing the group mean for each and every subject. B, The sex-specific mean is used. C, Regression to account for the value of an independent variable (x axis), but ignoring the subject's sex. D, A model that accounts for both the sex and the value of the x axis variable of each subject.
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Section editors: Tyler W. Barrett, MD; David L. Schriger, MD, MPH

Editor's Note: You are reading the 14th installment of Annals of Emergency Medicine Journal Club. The questions and the article they are about (Newgard et al. Ann Emerg Med. 2010;55:235-246) were published in the March 2010 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.