topic Re: using index to create a new variable in New SAS User

using index to create a new variable

epidemiologystu — Wed, 21 Apr 2021 12:05:45 GMT

Hello,

This piece of code is not correctly assigning all breast cancer cases. Could someone identify the error?

*create sample dataset;

data sample ;

input curr_topog_desc $30. ;

cards ;

Rectum NOS

Overlapping lesion of breast

Head of pancreas

Blood

Breast NOS

" " *meant to be blank;

;

run;

Data sample;

Set sample;

IF index(curr_topog_desc, "breast") ne 0 then do;

breastcancer = 1;

othercancer = 0;

end;

*if blank space, the person was not linked to cancer registry;

IF curr_topog_desc = " " THEN do;

breastcancer = 0;

othercancer = 0;

end;

*meant to capture all other cancers;

ELSE do;

breastcancer = 0;

othercancer = 1;

end;

run;

Re: using index to create a new variable

FreelanceReinh — Wed, 21 Apr 2021 12:42:03 GMT

Hello @epidemiologystu,

There are two issues:

The INDEX function is case-sensitive so that "breast" isn't found in "Breast NOS." Use the FIND function with the 'i' modifier instead:
```
find(curr_topog_desc, "breast", 'i')
```
or apply the LOWCASE function to the first argument:
```
index(lowcase(curr_topog_desc), "breast")
```
Without an ELSE before the second IF the values assigned in the first THEN branch are overwritten by the last ELSE DO/END block.

@epidemiologystu wrote:

data sample ;

input curr_topog_desc $30. ;

cards ;

Rectum NOS

Overlapping lesion of breast

Head of pancreas

Blood

Breast NOS

" " *meant to be blank;

Use a single period (.) to enter a missing value in data lines, not a blank in double quotes.

Re: using index to create a new variable

epidemiologystu — Wed, 21 Apr 2021 13:55:23 GMT

Thank you!!