So sorry, per diem is Latin for per day. I understand that the tapered regimen was ordered to more easily monitor the immediate effects of the Prednisone on the inflammatory process. As every body reacts slightly differently, it was easier for the specialist to determine the appropriate dosage. I had weekly contact with him,reporting my progress. The results and level of side effects determined the dosage. In the beginning I experienced asthma-like symptoms which diminished as my body began to tolerate, and the dosage reduced. Keep in mind that this is a dangerous drug if taken over the long term, but because of it's effectiveness in reducing inflammation, the risks were acceptable.