I was sent this paper by one of the authors, who is an endocrinologist at the same centre my son is treated at and with whom I have a good relationship.  My son has participated in these studies before, but I declined this one.  I was quite surprised by the papers findings as at least 2 of the authors consider that twice a day hydrocortisone is sufficient in the treatment of CAH (hence Shaun's comment that most patients were on twice daily administration).  I have been arguing this point with them for years and in fact changed my own son to thrice daily against the advice of one of the authors!    I have of course written, asking if their opinions have now changed and await a reply.  I also find it amazing that they have not changed their own patients medication timings, to coincide with what is recommended in the paper.  What is the point of research like this, if the authors do not practice what they preach!    I shall let you know the response I get, when received.