The Early Use of Blinding in Therapeutic Clinical Research of Neurological Disorders - The Early Use of Blinding in Therapeutic Clinical Research of Neurological Disorders - Open Access Pub

We sought to identify early uses of blinding in therapeutic clinical trials of neurological disorders by multiple search methods. A 1784 report by Benjamin Franklin and others described the evaluation of the use of Mesmerism to treat neurological and other syndromes including headache and epilepsy, using blindfolds and screens. This report demonstrated the usefulness of blinding to reduce bias in clinical research, yet despite this early discovery, blinding was not widely accepted or routinely used until the 20th century. Blinded clinical trials began to be used for various neurological syndromes in the 1950s, sporadically at first and then increasing in frequency in subsequent years. The reason for this delay is unclear, but we propose several hypotheses. DOI10.14302/issn.2470-5020.jnrt-15-803 Background Blinding/masking the allocation of subjects to treatment groups in therapeutic clinical research is now a well-established method to reduce the chance of bias and erroneous conclusions about safety or efficacy.1 A single-blind design, where subjects are unaware of their group assignment, can lessen the influence of the placebo effect on outcomes. A double-blind design, where the investigators are also unaware of subject group assignment, can minimize observer expectation bias. Both placebo effect and observer expectation bias are likely to be significant confounders in therapeutic clinical trials of neurological syndromes, because outcomes of interest to both patients and investigators often include a substantial subjective component. Despite the benefits of blinding, the general timeframe for its introduction to therapeutic clinical research of neurological disorders, however, is unclear. We sought to identify early examples of the use of blinding for this purpose. Blinding/masking the allocation of subjects to treatment groups in therapeutic clinical research is now a well-established method to reduce the chance of bias and erroneous conclusions about safety or efficacy.1 A single-blind design, where subjects are unaware of their group assignment, can lessen the influence of the placebo effect on outcomes. A double-blind design, where the investigators are also unaware of subject group assignment, can minimize observer expectation bias. Both placebo effect and observer expectation bias are likely to be significant confounders in therapeutic clinical trials of neurological syndromes, because outcomes of interest to both patients and investigators often include a substantial subjective component. Despite the benefits of blinding, the general timeframe