Very often the Principal Investigators know what info is sensitive or not and manage the process accordingly. In addition to this we also require of our CAB members to sign confidentiality agreements and keep this on file. I would think that the main strategy should be to develop long term relationships with CAB members, so that trust can develop. Although it should be trust based on mutual respect.
For example when we discuss a study protocol, we would ensure that only a study protocol is discussed which is actually related or relevant to that area (a study which in all probabability will be conducted in that area), because you do not want the wrong info to get out there in the community. At our site where we have multiple studies running, we have one CAB and regularly have training. Last year we held training in how to read a study protocol, supported by roleplay which was done by our Youth CAB, making use of peer education.
