This paper from Castillo et al states that the study was a “parallel pilot randomized open label, double-masked clinical trial”. I am not a trialist, so its surely my mistake, but how on earth can a study be open label and double-masked at the same time…?
These are the details they provide:
2.2.1. Randomization and masking
An electronically generated randomization 2:1 list was prepared by independent statisticians. The list was accessible only to nonmasked specialists in the study in an attempt to minimize observation bias. The patients’ data were recorded in the hospital’s electronic medical record, with blind access by the technical data collectors and the statistician who carried out the study.
Again, surely my mistake that I find this confusing, but I don’t really understand them. The patients and the statisticians were blinded, but the attending physicians not? But that’s rather just a guess…