CONDITIONAL SELECTION OF COMBINATIONS OF THREE VARIABLES USING ARRAY

[Cruise]

 I have to select patients who has specific combinations of conditions as following: 

 1. patients with both P2 and the Pa;

         OR

2. patients with both the P3 and the Pa;

Patients must have P2 and P3 with the Pa to be eligible. Simply put: P2+Pa, P3+Pa, P2+P3+Pa combinations are acceptable. 

data combinations; set have;
 array diagnosis[*] condition othercondition_1-othercondition_24;
  do i = 1 to dim(diagnosis);
   if diagnosis[i] in ('P2','P3') then x=1; 
   if diagnosis[i] in ('Pa')      then y=1;
   if x=1 and y=1 then output;
  end;
  drop i;
run;

However, resulting data "combinations" has an information for single subject (row) repeated 20 times. Very strange. Any idea why that happened? 

LOG: 

There were 95560 observations read from the data set WORK.HAVE.
NOTE: The data set WORK.COMBINATIONS has 20 observations and 66 variables.

Using SAS 9.4. 

[Reeza]

Use WHICHC() to create flags for each of your three variables and then use those variables to do your conditioning.

[Astounding · Accepted solution]

A simple solution:  move the OUTPUT statement.  Instead of coding it inside the DO loop, move it to after the END statement.