SAS程序问题

已知自变量x1和x2对事件y发生有影响，现在我想研究x1和x2对y连续发生时间间隔time的影响，根据文献此处应该用COX比例风险模型，但是我不理解COX比例风险模型需要有右删失变量完成回归分析，即
proc phreg data=
model time*y(0)= x1 x2/selection=stepwise ;
run;

想问问有人知道我这种情况，截尾变量y(0)应该是什么呢？

举例: 某肿瘤， 患者结局有2种情况： 死亡 c=1,   患者退出试验、试验结束时仍存活、违背试验方案退出 c=0 即为删失；T为生存时间

proc phreg data=
   model t*c(0)= sex agegrp smoke /selection=stepwise ;
run;



Survival data, therefore, are described by values of a pair of random variables, say (T, D). They can
be interpreted as follows:
• T represents the time that the subject was observed on study.
• D is an indicator of the fact that the event in question either occurred or did not occur at the
end of time T. The values of D might be 0 to indicate that the event did not occur and 1 to
indicate that it did. Then D = 0 means that the corresponding T is a censored time. Of
course, other values are possible.


资料参考：
1. https://blog.csdn.net/jaen_tail/article/details/79081954

自己顶一下