Re: Inherit past calculation of parameter in NONMEM

Dear Tingjie, It is possible to create a variable to store the last value, using IF-ELSE. However, more importantly I would suggest not to use functional forms for covariate models that allows restricting the typical CL to positive values only. Use a multiplicative parameterization of covariate effects, rather than additive - unless you know the additive is more mechanistic, e.g. high extraction over two different organs is independent, so that multiplicative may be inappropriate if you know the two covariates each affect only one of the two (and not the same organ). Set boundaries to covariate effects so that a covariate may not reduce by more than 100%, or use e.g. a power model, if covariate values are >0. Best regards Jakob Jakob Ribbing, Ph.D. Senior Consultant, Pharmetheus AB Cell/Mobile: +46 (0)70 514 33 77 [email protected] www.pharmetheus.com Phone, Office: +46 (0)18 513 328 Uppsala Science Park, Dag Hammarskjölds väg 52B SE-752 37 Uppsala, Sweden This communication is confidential and is only intended for the use of the individual or entity to which it is directed. It may contain information that is privileged and exempt from disclosure under applicable law. If you are not the intended recipient please notify us immediately. Please do not copy it or disclose its contents to any other person.