Masking of Trial Investigators

  • George HowardEmail author
  • Jenifer H. Voeks
Living reference work entry


The substantial investment of both time and money to mount a clinical trial would not be made without an underlying belief that the new treatment is likely beneficial. While a lack of definitive evidence can underpin the equipoise of investigators that is necessary to mount a new trial, the success in previous early phase trials (or even animal models) provides a natural foundation for an expected benefit in subsequent phase trials. Both investigators and patients can share this belief, and these expectations of treatment efficacy for new therapies introduce the potential for bias in clinical trials. The benefits, completeness, and reporting of masking in clinical trials are described, as they are approaches for implementing and maintaining the mask.


Masking Blinding Assessment of outcomes 


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Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.Department of BiostatisticsUniversity of Alabama at BirminghamBirminghamUSA
  2. 2.Department of NeurologyMedical University of South CarolinaCharlestonUSA

Section editors and affiliations

  • O. Dale Williams
    • 1
  1. 1.Department of MedicineUniversity of AlabamaBirminghamUSA

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