Hi, I want to input individual Bayesian parameter estimates obtained from poppk model fitting and simulate concentration-time profiles without variability under a given dose. I don’t see such an example in the user guide or nlme training manual. I have two issues/questions: 1) With the model in the attached project file, there are no error messages, but when I execute the simulation never finishes. 2) The model says I must define the parameters, which I did using the ‘fixef’ statements, but I want to reference the individual patient parameters mapped in the ‘parameters’ tab of the model. How do I do this in the model code? When I used ‘covariate()’ statements for each parameter, the model also froze (issue #1 above). Thanks, Mario [file name=20130807_ebe_sims.phxproj size=339742]Certara | Drug Development Solutions (332 KB)
Dear Mario I could do it with the population tab by just adding one fake random effect. The project corrected is attached with the last model being the one I generated. The easiest way for me was just to define all the individual parameters as covariate and having only one fake random effect that will not affect the simulation. I added also CObs1 and Cobs3 in the data set and an error model for both. For simulation it does not affect the outcome but Phoenix thinks usually in terms of fitting and therefore needs an error model. The code is as follows: test(){ deriv(A1 = - (CL12 * (C1 - C2))- (CL13 * C1)) deriv(A2 = (CL12 * (C1 - C2))) deriv(A3 = (CL13 * C1)- (CL3 * C3)) urinecpt(A0 = (CL3 * C3)) C1 = A1 / V1 dosepoint(A1, idosevar = A1Dose, infdosevar = A1InfDose, infratevar = A1InfRate) C2 = A2 / V2 error(CEps1=0.1) observe(Cobs1=C1+CEps1) C3 = A3 / V3 error(CEps3=0.1) observe(Cobs3=C3+CEps3) covariate(V1,V2,CL12,V3,CL13,CL3,wtkg,pres,dCL3dpres) V1a = V1 * wtkg V2a = V2 * wtkg CL12a = CL12 * wtkg V3a = V3 * wtkg CL13a = CL13 * wtkg CL3a = CL3 * wtkg * ((pres/9)^dCL3dpres) stparm(fake=tvfake+nfake) fixef(tvfake=c(,0.1,)) ranef(diag(nfake)=c(0.0000001)) } I ran it and got the results in 3 seconds. I hope it helps. best Regards; Serge [file name=20130807_ebe_sims_official.phxproj size=1147024]Certara | Drug Development Solutions (1.09 MB)