I am trying to build a Cox proportional hazards model using the coxph function in the survival package in R. My function call is:
m1=coxph(Surv(time=df$time, event=df$event,type=c('right')) ~ ln_num_prior_investments, data = df)
The model summary is as follows:
n= 1888, number of events= 707 coef exp(coef) se(coef) z Pr(>|z|) ln_num_prior_investments -0.03701 0.96367 0.02079 -1.78 0.0751 . --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Is the dependent variable in this model the survival time or the instantaneous hazard rate? I am trying to understand the directional impact of the ln_num_prior_investments variable, but the meaning of the sign in front of the coefficient will be different depending on whether it is the time or the hazard rate that is being modeled.