Clinical Trials

■■❚❙❘Chapter 8BlindingAmeet Bakhai, Sonia Patel, and Duolao WangRandomization can minimize the influence of bias in clinicaltrials by balancing groups for various characteristics. Bias canstill occur, however, if study personnel and patients know theidentity of the treatment, due to preconceptions and subjectivejudgment in reporting, evaluation, data processing, and statisticalanalysis. To minimize these biases, studies should be blinded,or masked, so that all participants are unaware of whether thesubjects are assigned to the new or standard therapy duringa trial. In this chapter, we discuss different study protocolsthat can be used to blind either the patients only, both patientsand investigators, or a combination of investigators, patients,sponsors, trial committees, and other personnel.75