Placebos that harm: sham surgery controls in clinical trials.

Recent debates over the use of sham surgery as a control for studies of fetal tissue transplantation for Parkinson's disease have focused primarily on rival interpretations of the US federal regulations governing human-subjects research. Using the core ethical and methodological considerations that underwrite the equipoise requirement, we find strong prima facie reasons against using sham surgery as a control in studies of cellular-based therapies for Parkinson's disease and more broadly in clinical research. Additionally, we believe that these reasons can be generalized to apply to the use of other placebo controls that carry significant risks of positive harms in and of themselves. As a result, our arguments are centrally relevant to the emerging drive to subject therapies with a surgical component to the same rigorous standards of evaluation as those governing the approval of new pharmaceuticals.