MGR ★ India, 20210930 09:35 (423 d 02:10 ago) Posting: # 22605 Views: 1,268 

Dear All, Need help on formula/procedure to find out the Intersubject Variability for a Full replicate design using SAS. Based on the Program given in the progesterone guideline below: PROC MIXED As there is no subj(seq) in the random statement, I am not able to calculate the intersubject variabilities for test and reference treatments. Please help me with this calculation. But when I use the proc varcomp procedure in SAS, I am able to generate the Variabilities (Inter and Intra) for test and reference treatments. My doubt is that whether it is acceptable by FDA regulatory? Thanks in Advance, — Regards, MGR 
ElMaestro ★★★ Denmark, 20210930 16:04 (422 d 19:41 ago) @ MGR Posting: # 22606 Views: 1,101 

Hi MGR, ❝ RANDOM TRT/TYPE=FA0(2) SUB=SUBJ G; Once you've run the model, the G matrix holds your betweensubject variability. I am not a SAS user, so the syntax for printing and processing G is outside my area of competence (like pretty much anything is). — Pass or fail! ElMaestro 
Helmut ★★★ Vienna, Austria, 20210930 17:25 (422 d 18:20 ago) @ MGR Posting: # 22607 Views: 1,205 

Hi MGR, like ElMaestro I’m not a SASian and my knowledge is limited. ❝ […] I am not able to calculate the intersubject variabilities for test and reference treatments. Please help me with this calculation. With the EMA’s example ‘Data set I’ (download CSV) you should get sumfink like:
In Phoenix/WinNonlin slightly different terms.
The first two lines give \(\small{\widehat{s_\textrm{bR}^2}}\) and \(\small{\widehat{s_\textrm{bT}^2}}\) and the last two \(\small{\widehat{s_\textrm{wR}^2}}\) and \(\small{\widehat{s_\textrm{wT}^2}}\). Ignore the third, which is the SubjectbyFormulation Interaction. Then as usual \(\small{100\sqrt{\exp \left ( \widehat{s_{\ldots}^2} \right )1}}\). Here \(\small{CV_\textrm{bR}=116.0\%,\;CV_\textrm{bT}=113.6\%,\;CV_\textrm{wR}=47.3\%,\;CV_\textrm{wT}=35.3\%}\). As ElMaestro wrote, you can get the estimated betweensubject variances also from Col1 of the estimated G matrix , where the 1^{st} Row is for R and 2^{nd} for T.❝ But when I use the proc varcomp procedure in SAS, I am able to generate the Variabilities (Inter and Intra) for test and reference treatments. Out of curiosity: Do they are agree with the results of Proc Mixed as outlined above?❝ My doubt is that whether it is acceptable by FDA regulatory? The betweensubject variabilities are not required for RSABE (in the FDA’s Summary Table 3B you have to give only the withinsubject variance and standard deviation of the reference). For ABE (Table 3A) variances are not required at all. Post 22,000… — Diftor heh smusma 🖖🏼 Довге життя Україна! _{} Helmut Schütz The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes 