CODEWITHSUNDEEP
sas
DOT
DOT

Reputation: 329

SAS LOOP - create columns from the records which are having a value

Suppose i have random diagnostic codes, such as 001, v58, ..., 142,.. How can I construct columns from the codes which is 1 for the records?

Input:
            id found  code
            
            1   1      001
            2   0      v58
            3   1      v58
            4   1      003
            5   0      v58
    ......
    ......
    15000   0      v58

Output:
id code_001 code_v58 code_003 .......
1    1       0        0
2    0       0        0
3    0       1        0
4    1       0        0
5    0       0        0
.........
.........

Upvotes: 3

Views: 221

Answers (1)

Richard
Richard

Reputation: 27498

You will want to TRANSPOSE the values and name the pivoted columns according to data (value of code) with an ID statement.

Example:

In real world data it is often the case that missing diagnoses will be flagged zero, and that has to be done in a subsequent step.

data have;
input id found  code $;
datalines;            
1   1      001
2   0      v58
2   1      003  /* second diagnosis result for patient 2 */
3   1      v58
4   1      003
5   0      v58
;

proc transpose data=have out=want(drop=_name_) prefix=code_;
  by id;
  id code;   * column name becomes <prefix><code>;
  var found;
run;

* missing occurs when an id was not diagnosed with a code;
* if that means the flag should be zero (for logistic modeling perhaps)
* the missings need to be changed to zeroes;

data want;
  set want;
  array codes code_:;
  do _n_ = 1 to dim(codes);   /* repurpose automatic variable _n_ for loop index */
    if missing(codes(_n_)) then codes(_n_) = 0;
  end;
run;

Upvotes: 3

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