Hi everyone,
I am trying to analyze survival data and want to use a change-point model to describe the hazard over time. I want to estimate the “time” of the change-point rather than manually specify this. I was wondering how to estimate this change-point time in NLME. Is there a function similar to MTIME in NONMEM – I was thinking that we may be able to do this in the sequence statement?
Thanks,
Hechuan
Dear Hechuan
I am not sure what you are looking for but if it is to take actions at unknown times (defines as structural parameters you estimate), then you can do it with sequence. What I need is more clarification about what are the actions you are taking.
If you have the NONMEM code, it would help a lot. I will try to make an example.
Best Regards
Serge
[quote=“minhaj mohd, username:minhaj”]
Dear Hechuan
I am not sure what you are looking for but if it is to take actions at unknown times (defines as structural parameters you estimate), then you can do it with sequence. What I need is more clarification about what are the actions you are taking.
If you have the NONMEM code, it would help a lot. I will try to make an example.
Best Regards
Serge
[/quote]mtime_example.phxproj (94.2 KB)
Dear Heshuan.
I atatched a project where we want to change the rate of infusion at unknown times (tlag1,tlag2 and tlag3).
Sequence advacnes by tlag1 then by tlag2 then by tlag3. These are relative times and therefore you do not need to remember what was the previosu time. The program will estimate tlag1 , tlag2 and tlag3.
Is it somehting like that you are looking for.
Let me know;
Best
Serge
Hi Dr. Guzy,
This is exactly what I want. The example project works well.
Cheers!
Hechuan