@lyfaqu wrote: I am trying to dichotomise a few variables using a 0.5 threshold.    %MACRO dichot(dichVar=); data quasi.MVNdi; set quasi.MVN; %if &dichVar < 0.5 %then &dichVar = 0; %else &dichVar = 1;; /*WHY THERE HAS TO BE 2 SEMICOLONS*/ RUN; proc print data=quasi.mdi; var &dichVar; run;; %MEND dichot;   %dichot(dichvar=Latest_lipid_drug); %dichot(dichvar=Latest_diabetes);   somehow the results that came out were all 1 (for both variables, original values are normally distributed between -1 to 1).   Anywhere wrong with the code? Thanks. Basically I do not see any need for a macro anywhere. Any time you see a requirement to do the exact same thing to multiple variables think ARRAY instead and process all of them at once Some thing like: data quasi.MVNdi; set quasi.MVN; array di Latest_lipid_drug Latest_diabetes ; do i = 1 to dim(di); if not missing di[i] then di[i]= di[i] ge 0.5; end; drop i; RUN; Likely Problems: 1) You overwrite the output data set with each call for a single variable 2) total execution time increases with more variables. 3) You need to be careful with <  or <= comparisons about whether you want missing values included or not. Missing is < any explicit value 4) Since macro variables are compared at the compilation phase you aren't generating the code you think you are.   %if DOES NOT evaluate data step values but macro variable values.   As for why the two semicolons: run your code like this: options mprint symbolgen; %dichot(dichvar=Latest_lipid_drug); to see what the macro is generating.       the t ... View more