topic Re: Create a new variable in New SAS User

Create a new variable

MisterJenn — Wed, 23 Nov 2022 21:16:08 GMT

I am new to SAS. I am trying to figure out the best way to create a new variable with the following directions:

Create a new variable called age_bmicat according to the specifications in the table below:

Re: Create a new variable

PaigeMiller — Wed, 23 Nov 2022 22:46:00 GMT

In a SAS data step

if age<=65 and (bmi<18 or bmi>25) then age_bmicat=1;

Using that as an example, see if you can figure out the code for the rest of the problem.

Re: Create a new variable

Reeza — Wed, 23 Nov 2022 22:43:44 GMT

data want;
set have;

if age <= 65 then do;
    if  18 <= bmi <= 25 then age_bmicat = 2;
    else if age_bmicat < 18 or age_bmicat > 25 = 1;
end;
else if age > 65 then do;
    if  25 <= bmi <= 30 then age_bmicat =  4;
     else if age_bmicat < 25 or age_bmicat > 30 = 3;
end;

run;

@MisterJenn wrote:

I am new to SAS. I am trying to figure out the best way to create a new variable with the following directions:

Create a new variable called age_bmicat according to the specifications in the table below:

Re: Create a new variable

tarheel13 — Sat, 26 Nov 2022 18:06:53 GMT

haven't seen your data but you should do this check anyway:

data bmi;
   set prac.chol_new;
   if nmiss(ht,wt)=0 then do;
      bmi=703*(wt/(ht**2));
   end;
   
   if nmiss(age,bmi)=0 then do;
      if age le 65 then do;
         if bmi < 18 or bmi > 25 then age_bmicat=1;
         else age_bmicat=2;
      end;
      else do;
         if bmi < 25 or bmi > 30 then age_bmicat=3;
         else age_bmicat=4;
      end;
   end;
run;

proc means data=bmi n nmiss min max;
   class age_bmicat / missing;
   var age bmi;
run;

Note, it is important to only create the new categorical variable when age and BMI are both nonmissing.