st: Interaction between continious and categorical variable in Cox model

[Sanam P <sanamp25@yahoo.com>]

Dear Statalisters,

I have included interaction between a categorical variable with 4 levels with a continuous variable in a Cox regression model using :
  
xi:stcox ... i.categorical*continuous

The model now include below variables involved in the interaction, with their Hazards ratios and p-values. 

 
Categorical-2
Categorical-3
Categorical-4
Continuous
Categorical X continious~2
Categorical X continious~3
Categorical X continious~4
 
I think that  HR of "categorical-2"  means the risk in second category of the categorical variable compared with first category when the continious variable is equal to zero. and the hazards related to the "continiuos' means the slope of the continious variable at first level of the categorical variable.
 
I was wondering whether you could kindly guide me how to calculate and interpret hazards for the last 3 terms involved in the interaction term. 
 
Many thanks,
Sanam


      


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