Open‐Labeled Trial

This article discusses open-labeled studies; that is, studies that are not blinded. It is usually assumed that lack of blinding is “total,” not just single-blinded (either patient- or investigator-blinded). Different levels and aspects of blinding can often be achieved so that trials may be only partially open label. In some cases, open-label trials might be practically more acceptable, and in some studies, they may even be preferred to blinded studies. Keywords: blinding; masking; concealment; bias; endpoints; pragmatic trials