SAS phreg。如何划分数据集进行分离分析？

Question

SAS数据集包括来自两个中心（= 1和2）的数据。如何分别为每个中心制作phreg？

proc phreg data = a;
INPUT center time censor gender;
class gender;
model time*censor(0) = gender; 
run;

Answer 1

proc sort data = a;
 by center;
run;
proc phreg data = a; 
 input time censor gender;
 class gender;
 model time*censor(0) = gender;
 by center;
run;

是一种方式。另一个是

proc phreg data = a; 
 input time censor gender;
 class gender;
 model time*censor(0) = gender;
 where center = 1;
run;

然后再用center = 2

再做一次