topic Re: How do I check if a variable includes certain values if this variable contains multiple values? in SAS Programming

How do I check if a variable includes certain values if this variable contains multiple values?

Boon_Noob — Wed, 05 Jan 2022 22:33:35 GMT

Person	All the Diagnosis codes for this Person
1	1,2,4
2	2,3,4
3	5,6,7
4	1,2,3,4

If I have a dataset that looks like this, where a variable column contains multiple values per row. So one person can have multiple codes. Here I want to define a new variable that if a person's codes contains either 2 or 3, then new variable =1 otherwise new variable =0.

I want something like this:

ID	Diagnosis code	New_Var
1	1,2,4	1
2	2,3,4	1
3	5,6,7	0
4	1,3,4	1

Re: How do I check if a variable includes certain values if this variable contains multiple values?

Tom — Wed, 05 Jan 2022 22:47:12 GMT

Assuming your dataset is named HAVE and your character variable with the list of codes is named DIAGNOSIS_CODE then use code like:

data want;
  set have;
  new_var = indexw(diagnosis_code,'2') or indexw(diagnosis_code,'3');
run;

Re: How do I check if a variable includes certain values if this variable contains multiple values?

Reeza — Wed, 05 Jan 2022 22:47:21 GMT

FINDW() or restructure your data to a more logical structure that has each value in it's own column or mulitple rows per ID.

Re: How do I check if a variable includes certain values if this variable contains multiple values?

novinosrin — Wed, 05 Jan 2022 22:49:01 GMT

data have;
input Person	Diagnosis_codes :$10.;
cards;
1	1,2,4
2	2,3,4
3	5,6,7
4	1,2,3,4
;

data want;
  set have;
  New_Var=^^findc(Diagnosis_codes,'23');
run;

Re: How do I check if a variable includes certain values if this variable contains multiple values?

ballardw — Wed, 05 Jan 2022 22:52:09 GMT

It helps to provide example data in the form of a data step so we have something to write code to test and at least your actual variable names.

Something like this should work for your specific example:

data want; 
    set have;
    new_var = (index(diagnosiscodes,'2')>0 or index(diagnosiscodes,'3') > 0);
run;

The index function returns a position number in the string searched. The first parameter is the string to search, the second is what to search for. If the value is not found then the function returns 0.

SAS will return a value of 1 for "True" and 0 for "False". So comparisons are a quick way to create 1/0 coded values.

You will find in the long run that placing multiple values into a single variable is awkward to code with and may result in very complex processes that do not extend well when new values are added.

Re: How do I check if a variable includes certain values if this variable contains multiple values?

Boon_Noob — Thu, 06 Jan 2022 15:08:01 GMT

Thanks for the reply! If I have multiple rows per ID, how should I code it?