Parameter %RSE vs ETA %RSE

From: Daniel Corrado <daniel_corrado@yahoo.com> Subject: [NMusers] Parameter %RSE vs ETA %RSE Date: 7/17/2003 1:57 PM The results of my Nonmem modeling of a sparse data set are given below * 1 comp model with CL, V and Ka * Successful minimization * Covariance matrix obtained * goot obs vs pred and obs vs ipred plots THETA1 = CL = 1.66e+003; %RSE = 3.2% THETA2 = V = 2.04e+003; %RSE = 32.9% THETA3 = KA = 0.196; %RSE = 10.4% Errors ETA1 = 0.0230; %RSE= 65.2% (CI bound zero) ETA2=1.36; %RSE = 39.1% ETA3=6.70e-008; %RSE 1.37e+008%(CI bound zero) A colleague of mine indicated that the large %RSE associated with ETA3 indicats that ETA3 and by association THETA3(KA) estimations were not very good. He suggested that I fix KA prior to modeling and try to estimate only CL and V. My contention is that the value of KA obtained is in the ball park of that seen from dense data studies. Also %RSE associated with THETA3 is small. The value of ETA3 is so small that the high %RSE associated with it still makes it insignificant when compared to THETA3. Also the %CV for ETA 3 = 0.03% despite the large %RSE. Hence the value of KA and ETA3 are ok. Could someone let me know if my line of reasoning if totally off. Thanks, Dan