In my dataset from an actual clinical trial, I have 64 ID numbers (numbered 1 to 64), where 32 goes to treatment group A and 32 goes to treatment B and a score (outcome)
So I want to add a hypothetical variable where I want to generate a variable (let's call it Gender/Sex, so 2 levels) that is sex is evenly and randomly distributed within each group (16 males and 16 females per treatment group). How do I do this randomly?
If you use survey select you can name your strata:
proc surveyselect data='trial' method=srs n= 'sample size'
seed= 'number' out='trial sample;
strata "enter strata here, gender sex with no column, try both and see what gives you the desired output"
run;
I put everything you'll need to type in quotes. Hope this helps.
Well, that statisticians out there probably have the best answers for this. My way would be:
data want;
call streaminit(123);
set have;
male_cnt=0;
female_cnt=0;
if rand("uniform") <0.5 then do;
if male_cnt <16 then do;
sex="male";
male_cnt=male_cnt+1;
end;
else do;
sex="female";
female_cnt=female_cnt+1;
end;
else do;
/* same as above but reveresed */
end;
run;
Probably a bit simplistic and not so random, but if it doesn't matter too much...
If you use survey select you can name your strata:
proc surveyselect data='trial' method=srs n= 'sample size'
seed= 'number' out='trial sample;
strata "enter strata here, gender sex with no column, try both and see what gives you the desired output"
run;
I put everything you'll need to type in quotes. Hope this helps.
thanks that worked for me. I used that to randomly select the men.. and then if the sex variable is missing, i pop recoded that to women.
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