10-InformationBias

10-InformationBias - 3/22/2011 Sources of error:...

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Unformatted text preview: 3/22/2011 Sources of error: Information bias 1 Sources of error: Information bias Principles of Epidemiology for Public Health (EPID600) Victor J. Schoenbach, PhD home page Department of Epidemiology Gillings School of Global Public Health University of North Carolina at Chapel Hill www.unc.edu/epid600/ 11/5/2001 Sources of error: Information bias 2 Abort, Retry, Fail Tips for safer drives: Never turn off a PC or accessories while the computer is on or the disk is active. USA Today [ PC Magazine , 10/3/1996] Chapter 1 THE HISTORIAN'S TASK: Insight into the future History, a record of things left behind by past generations, started in 1815. Thus we should try to view historical times as the behind of the present. Anders Henriiksson (ed), Non Campus Mentis , NY, Workman Publishing Co., 2003 Non Campus Mentis History, as we know, is always bias, because human beings have to be studied by other human beings, not by independent observers of another species. Anders Henriiksson (ed), Non Campus Mentis , NY, Workman Publishing Co., 2003, chapter 1 3/22/2011 Sources of error: Information bias 5 Information bias Information bias : a systematic distortion or error that arises from the procedures used for classification or measurement of the disease, the exposure, or other relevant variables. 3/22/2011 Sources of error: Information bias 6 Information bias Classification or measurement Differential or nondifferential bias Direction of bias Misclassification of covariables 3/22/2011 Sources of error: Information bias 7 Classification or measurement Data for epidemiologic studies consist of classifications (e.g., hypertensive vs. normotensive) or measurements (e.g., 120 mmHg systolic BP). Possible sources of measurement or classification error include instrumentation, laboratories, records, respondents; data collectors, managers, analysts, and interpreters. 3/22/2011 Sources of error: Information bias 8 Sources of measurement error Respondent (interview, questionnaire): inability to understand, recall, articulate; unwillingness to disclose social desirability influences Can be influenced by wording of questions and how they are asked. 9...
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This note was uploaded on 03/12/2012 for the course EPID 600 taught by Professor Staff during the Spring '08 term at UNC.

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10-InformationBias - 3/22/2011 Sources of error:...

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