SAS phreg。如何劃分數據集以進行分離分析？

Question

SAS數據集包含來自兩個中心（= 1和2）的數據。如何分別爲每個中心製作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; 

是單向的。另一種是

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

，然後用中心做一遍= 2