data wanted;
set aaa;
retain treat1 x0 x1;
x1=x;
x0=lag(x1);
if visit=6 then treat1=substr(treat,1,1);
else if visit=10 then treat1=substr(treat,2,1);
if lag(id) ne id then delete;
drop x visit;
run;

data aaa1;
set aaa;
if visit=6 then  treat1=substr(treat, 1,1);
else if visit>6 then  treat1=substr(treat, 2,1);
run;
proc sort; by id treat1;run;

data baseline(drop=visit);
set aaa(rename=(x=x0));
if visit=2 then  do;        treat1=substr(treat, 1,1); output; end;
else if visit=6 then do;  treat1=substr(treat, 2,1); output; end;
run;
proc sort; by id treat1;run;

data aaa2(rename=(x=x1)); ;
merge aaa1(in=a) baseline(in=b);
by id treat1;
if a and b;
run;
proc sort data=aaa2 out=aaa3(drop= visit);
by id visit;
run;

请跟帖以出售60论坛币的形式，我来购买，谢谢！

请跟帖以出售60论坛币的形式，我来购买，谢谢！