An unusual word – I came across it in an article in the Australian Bulletin magazine ( now sadly defunct). It was used in reference to the role Queen Elizabeth II plays to the political leaders of her time. Prime Ministers and Presidents of many countries found that they could unburden themselves in complete secrecy within her presence.
For them used to the back stabbing treachery and lies of current political life to be in the presence of someone who had no motive or inclination to talk to someone else or post on social media was profound.
An element of this is present in a confidential medical discussion between a practitioner and their client.
I came across the following quote from an oncologist talking about the Australian My Health record system ”When a patient reveals their secrets to a Dr they trust in the doctor patient relationship, not in the Doctor- patient government or the Doctor patient tax office relationship”
Source R. Srivastava Guardian July 30 2018 online edition.
This quote is talking about the same thing from a Medical Doctors point of view. I am a member of a professional association whose own rules mirror this – The Client’s health records and confidences are held in the strictest privacy.