Assessing the Success of the Blind in Sham-Controlled Randomized Clinical Trials

• Activity Number: 518
• Type: Topic Contributed
• Date/Time: Wednesday, August 7, 2013 : 10:30 AM to 12:20 PM
• Sponsor: Biopharmaceutical Section
• Author(s): Valerie Durkalski*+ and Qi Wu
• Companies: Medical University of South Carolina and Medical University of South Carolina
• Keywords: sham-controlled trials ; blinding ; randomized controlled trials

Abstract

A critical component to randomized-controlled clinical trials is the inclusion of adequate treatment blinding to help ensure unbiased estimates of treatment effects. Although a common design feature, several trials, particularly device and surgical trials, are challenged to develop adequate controls. When feasible, these trials attempt to preserve the blind by developing a 'sham' control that mimics the experimental treatment. In these cases, it is important to assess the quality of blinding and the impact on the treatment estimates. Options for assessment include questionnaires of 'best' treatment guess and confidence in the guess which should be collected at multiple timepoints throughout the trial period. We examine the use of these questionnaires in two sham-control trials and the relationship between blinding quality and treatment effect.