Dear NMusers, In the past I have used the logit transform to obtain IIV on F in NONMEM and used the following equations to get F1 and the SD on F1: TVF = THETA(.)/(1-THETA(.)) LTVF= LOG(TVF) + ETA(.) F1 = EXP(LTVF)/(1+EXP(LTVF)) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ s.d.F1=SQRT(OMEGA)*THETA(.)*(1-THETA(.)) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ However, recently I had to implement IOV and covariate effects on TVF. I came up with these equations but I am not sure if the SD equations below are valid. Furthermore, can I give a broader meaning or definition to the SD other than the SD for a median BMI of 25. OC1 = 0 OC2 = 0 OC3 = 0 IF (OCC.EQ.1) OC1 = 1 IF (OCC.EQ.2) OC2 = 1 IF (OCC.EQ.3) OC3 = 1 QCC1=OC1*ETA(x) QCC2=OC2*ETA(y) QCC3=OC3*ETA(z) IOV=QCC1+QCC2+QCC3 TVF = THETA(x)*((BMI/25)**(THETA(y))) IF (TVF.GE.1) TVF=.99 TPH = LOG(TVF/(1-TVF)) F1 = EXP(TPH+ETA(.)+IOV)/(1+EXP(TPH+ETA(.)+IOV)) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ s.d.F1.IIV=SQRT(OMEGA.IIV)*(TVF.for.BMIof25)*(1-(TVF.for.BMIof25)) s.d.F1.IOV=SQRT(OMEGA.IOV)*(TVF.for.BMIof25)*(1-(TVF.for.BMIof25)) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Kindly advice...MNS
