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Blindness

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Fundamentals of Clinical Trials

Abstract

In any clinical trial, bias is one of the main concerns. Bias may be defined as systematic error, or “difference between the true value and that actually obtained due to all causes other than sampling variability” [1]. It can be caused by conscious factors, subconscious factors, or both. Bias can occur at a number of places in a clinical trial, from the initial design through data analysis and interpretation. One general solution to the problem of bias is to keep the participant and the investigator blinded, or masked, to the identity of the assigned intervention. One can also blind several other aspects of a trial including the assessment, classification, and evaluation of the response variables. Large sample size does not reduce bias although it generally improves precision and thus power.

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Author information

Authors and Affiliations

  1. Bethesda, MD, USA

    Lawrence M. Friedman

  2. School of Medicine, Wake Forest University, Winston-Salem, NC, USA

    Curt D. Furberg

  3. Department of Biostatistics & Medical Informatics, University of Wisconsin, Madison, WI, USA

    David L. DeMets

Authors
  1. Lawrence M. Friedman
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  2. Curt D. Furberg
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  3. David L. DeMets
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Corresponding author

Correspondence to Lawrence M. Friedman .

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© 2010 Springer New York

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Friedman, L.M., Furberg, C.D., DeMets, D.L. (2010). Blindness. In: Fundamentals of Clinical Trials. Springer, New York, NY. https://doi.org/10.1007/978-1-4419-1586-3_7

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