topic Creating two dummy variables in SAS Programming

Creating two dummy variables

westbestern — Wed, 10 Nov 2021 20:00:46 GMT

I'm creating dummy variables for the first time!

I am using data from NHANES.

I have a variable smoke_hx where 0= never smoked, 1=past smoker, 2=current smoker.

I want to create the variables ever_smoked1 that is a dummy for smoke_hx=1 and ever_smoked2 which is a dummy for smoke_hx=2. Never smoked is the reference group.

How do I create these dummy variables? I've read a bunch of explanations but nothing is making sense!

Re: Creating two dummy variables

Reeza — Wed, 10 Nov 2021 20:09:05 GMT

Why?
If the CLASS statement exists with in the procedure it will do the dummy coding for you, no need to do that manually.

Re: Creating two dummy variables

westbestern — Wed, 10 Nov 2021 20:21:56 GMT

Good to know! But for this class, my professor is requiring us to manually create them. This is the code I have. Not sure if it's correct.

@Reeza wrote:
Why?
If the CLASS statement exists with in the procedure it will do the dummy coding for you, no need to do that manually.

data data2;
set data1;
	if smoke_hx=1 then ever_smoked1=1;
	else ever_smoked1=0;
	if smoke_hx=2 then ever_smoked2=1;
	else ever_smoked2=0;
	run;

Re: Creating two dummy variables

Reeza — Wed, 10 Nov 2021 20:25:09 GMT

Your code looks correct then. You can check it though, using proc freq.

proc freq data=data2;
table smoke_hx*ever_smoked1 / list;
table smoke_hx*ever_smoked2 / list;
run;