I have a model that seems to be behaving strangely, looking for interpretation help
in model building, the OBJ is usually ~20900. Until this model, where, on the covariance step (IMPMAP method) the OBJ drops 9000 points (20798 to 11837), monitoring from output file below iteration 70 OBJ= 20798.6782833867 eff.= 5530. Smpl.= 10000. Fit.= 0.99524 Convergence achieved iteration 70 OBJ= 11837.9045704476 eff.= 5475. Smpl.= 10000. Fit.= 0.99522 Parameters don't change much (edited .ext file below). 50 1.35E+01 9.96E-01 4.42E-02 9.41E-01 3.05E+01 1.29E-01 20799.68932 60 1.35E+01 9.67E-01 4.45E-02 9.43E-01 3.05E+01 1.29E-01 20792.90665 70 1.35E+01 9.73E-01 4.44E-02 9.44E-01 3.05E+01 1.29E-01 20798.67828 70 1.35E+01 9.73E-01 4.44E-02 9.44E-01 3.05E+01 1.29E-01 11837.90457 Plots don't look particularly different than other model (and look pretty good), p values for ETAs are very reasonable, it converges, condition # is good. Only two issues: RSE for 2 OMEGAs is a little large (0.5) an interoccasion variability term (on V) is very large (~4, exponential). This is, I think, related to many subjects with data only at steady state. Further, when I advance this model, add another covariate, or another IOV on CL, to address the issue with SS data, cannot identify Volume uniquely (using the final parameter from this model as the initial in the next model), I cannot reproduce these results - the OBJ goes back to ~20,800, with essentially the same parameter estimates. So I end up rejected all additional covariates in this model (at least by LRT). other details, running on Windows, 64 bit, Intel compiler, NONMEM version 7.3. Can I believe this OBJ value? Should I base an additional hypotheses on the SEE, rather than the LRT? But, basically, why is this happening? thanks Mark Sale M.D. Senior Vice President, Pharmacometrics Nuventra Pharma Sciences, Inc. 2525 Meridian Parkway, Suite 200 Durham, NC 27713 Phone (919)-973-0383 ms...@nuventra.com<ms...@kinetigen.com> CONFIDENTIALITY NOTICE The information in this transmittal (including attachments, if any) may be privileged and confidential and is intended only for the recipient(s) listed above. Any review, use, disclosure, distribution or copying of this transmittal, in any form, is prohibited except by or on behalf of the intended recipient(s). If you have received this transmittal in error, please notify me immediately by reply email and destroy all copies of the transmittal.
