Bias in Evidence-based Medicine

Sidonie N. Lavergne, DVM, IPSAV, PhD, Postdoctoral Fellow

Assistant Professor, College of Agricultural, Consumer and Environmental Sciences, Division of Nutritional Sciences, University of Illinois

Proceedings Paper (PDF) Slides (PDF) Screencast (video)
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There are various definitions of the word bias, such as “an unfair personal opinion that influences judgment” or “tendency or preference towards a particular perspective, ideology or result, especially when the tendency interferes with the ability to be impartial, unprejudiced, or objective”. In addition to impacting our personal life, biases also impact biomedical research (funding, study outcome, and publication) and clinical decisions. It is important for clinicians and clinical researchers to understand what biases are in order to avoid them. After emphasizing these points, the presentation will also introduce the audience to the different types of bias in biomedical science and medicine: personal biases (e.g. culture background, past experiences, personal conflict of interest); scientific biases (e.g. selection, performance, attrition, professional conflict of interest); and confounding factors. Finally, the webinar will explain how each type of bias can either be avoided or how researchers and clinicians can limit their impact on a study outcome or clinical decision: e.g. randomization; blinding; intent-to-treat.


bias, confounding factor, conflict of interest, randomization, blinding

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