RE: Lognormal survival in NONMEM?

From: [email protected] <[email protected]> On Behalf Of Jakob Ribbing Sent: 29 August 2019 16:18 To: [email protected] Subject: Re: [NMusers] Lognormal survival in NONMEM? Dear Rik, There are very nice code examples (for NONMEM) in this poster-material from Nyberg et al.: https://www.page-meeting.org/pdf_assets/404-Poster_PAGE%20_2014_tte_sim_joakim_nyberg_with_code.pdf These include the log-normal distribution, as well as Gompertz and Weibull. Best regards Jakob Jakob Ribbing, Ph.D. Senior Consultant, Pharmetheus AB Cell/Mobile: +46 (0)70 514 33 77 [email protected]<mailto:[email protected]> http://www.pharmetheus.com/ Phone, Office: +46 (0)18 513 328 Uppsala Science Park, Dag Hammarskjölds väg 36B 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. On 29 Aug 2019, at 15:33, Rik Schoemaker <[email protected]<mailto:[email protected]>> wrote: Dear all, Playing with repeated time to event models, I run into the issue that simple diagnostics for a single time to event outcome suggest that constant hazard and Weibull models are not very appropriate. The lognormal model seems to provide a very nice fit; compared to a constant hazard, the hazard is suggested to be higher in the beginning and then significantly lower at later times. I have not seen any implementations online: does anyone know if the lognormal survival function can be implemented in NONMEM, and/or can anyone suggest alternative approaches? Some time-varying function to modify the hazard? Any and all suggestions appreciated! Kind regards, Rik Rik Schoemaker, PhD Occams Coöperatie U.A. Malandolaan 10 1187 HE Amstelveen The Netherlands http://www.occams.com/ +31 20 441 6410 [email protected]<mailto:[email protected]> <image001.png>