Hi. I am trying to build a population model for a DDI study in which subjects received either PROBE drug or PROBE + INHIBITOR in two separate phases. To get started I am running an individual model for initial estimates (see attached model file). I am using the II, ADDL and RESET columns but when I run the model, there is a continuous “prediction” line between the first phase and the second phase. Is this to be expected? Is there a way to make a clean break between phases without sorting on TRT (treatment)? Do I have the RESET column/Input Option set up correctly? [file name=DDI_Model.phxproj size=360589]Certara | Drug Development Solutions (352 KB)
It’s normal for it to have a line connecting the points between the two phases. If you want to make a column lattice condition for phase, you would need to send the “residuals” worksheet to a Merge Worksheets (to merge phase information back in) and then to an XY Plot. Your input options appear to be correct, but to confirm you can also check the dosing worksheet (in the Results tab) to make sure NLME correctly interpreted your input for the dosing information. By the way, you should upgrade to 6.2. It has more features than 6.1, especially for NLME. If you’re already working with NLME, it would not be difficult to transition to the newer version. The new version can be downloaded from this link: ftp://support_ftp:pt9JTmD9GdXQLtCgPkvL@ftp.certara.com/support/desktop/Phoenix/Phoenix_1.2.1.zip