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Avoiding bias in observational studies: part 8 in a series of articles on evaluation of scientific publications

Gaël P Hammer1, Jean-Baptist du Prel, Maria Blettner

  • 1Institut für Medizinische Biometrie, Epidemiologie und Informatik, Universitätsmedizin der Johannes Gutenberg-Universität Mainz. ghammer@uni-mainz.de

Deutsches Arzteblatt International
|December 1, 2009
PubMed
Abstract

Keywords:
clinical researchdata analysisepidemiologyobservational studystudy

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Bias refers to any tendency that prevents a question from being considered unprejudiced. In research, bias occurs when one outcome or answer is selected or encouraged over others in sampling or testing. Bias can occur during any research phase, including study design, data collection, analysis, and publication.
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