I am studying the impact of temperature on the onset of flowering of trees. I am using a cox model for time dependent covariates as implemented in the R package survival. I only have one (cumulative) time dependent covariate, that is daily growing degree days (GDD, calculated from daily min and max temperature).
My results look something like this:
coef exp(coef) se(coef) z Pr(>|z|) 0.0117237 1.0117927 0.0004184 28.02 <2e-16 ***
Now my question: I understand a hazard ratio of 1.01 would mean that a unit increase in my time dependent covariate increases the risk of death by 1%, however, in my case all trees are expected to flower.
What I want to know is whether a unit increase in my time dependent covariates causes earlier flowering. I this information contained in the hazard ratio, or am I doing something wrong?