Hi all, I am using the coxme function to fit random effects survival models. The base survival models show a typical "J" shaped curve where survival drops sharply then plateaus over time interval. I want to include a time covariate which could account for this non-linear decrease in survival over time. However, I have not found a clear way to do this in the coxme models. Any suggestions would be greatly appreciated. Below is some sample code and data. -Jared selection=coxme(Surv(start,stop,status)~prob+(1|year); fawn status start stop prob year 3 0 0 86 0.83 2009 4 1 0 9 0.6 2009 5 0 0 355 0.63 2009 6 1 0 6 0.52 2010 7 0 0 68 0.79 2010 8 0 0 354 0.69 2010 9 1 0 3 0.72 2010 10 1 0 4 0.77 2010 11 1 0 12 0.62 2010 13 0 0 82 0.7 2011 14 1 0 7 0.67 2011 15 1 0 74 0.49 2011 16 0 0 351 0.64 2011 17 0 0 351 0.74 2011 18 0 0 82 0.72 2011 19 1 0 342 0.69 2011 [[alternative HTML version deleted]]