Perfect!!!   The code you shared works in 100 percent perfection.  And I had accepted this as Solution.   Could you please help me understand how does this code work. I just tried your code blindly. And worked. But, did not understand the logicality of it. I am really not as techy as you.   Kudos to you technical skill.       ... View more

Again,, there was a typo. Please execuse me. Please read the last 4 records as below, 14 Visit2 545450 1 14 Visit2 3434454 1 14 Visit3 545450 1 14 Visit3 3434454 1 ... View more

Adding to above, Please read the last 4 records as below, There is a typo for this patient. 14 Visit2 545450 1 14 Visit2 3434454 1 14 Visit3 3434454 1 14 Visit3 3434454 1 ... View more

I appreciate you for your sincere effort on this tricky problem. The solution you have provided was covering my code for Patient 1 and 12. But not for 13 and 14. I have added the scenario here for reference with the desire output. Please have a look.   data have; infile cards truncover; input PatientID Visit $ Medication reCalc; cards; 1 Visit1 111111  1 Visit2 222222  1 Visit2 33333  1 Visit3  . 1 1 Visit4 888888  12 Visit1 34343  12 Visit2 12345  12 Visit2 67891  12 Visit2 54321  12 Visit4  . 1 12 Visit5 43333  12 Visit6  . 1 13  Visit1  454545 13  Visit1  778788 13  Visit2  .  13 Visit3 .  13  Visit4 . 13  Visit5  . 13  Visit6 . 13  Visit7  . 1 14 Visit1 545450 14  Visit1 3434454 14 Visit2  . 1 14  Visit3 . 1 ; Run;   Desire Output :   PatientID  Visit Medication  reCalc 1  Visit1 111111    1 Visit2 222222    1 Visit2  33333    1 Visit3 222222  1 1 Visit3 33333  1 1 Visit4 888888    12   Visit1 34343    12 Visit2  12345    12   12  Visit2 67891    12 Visit2  54321    12 Visit4  12345  1 12 Visit4  67891  1 12 Visit4  54321  1 12   12 Visit5 43333    12 Visit6  43333  1 13   Visit1  454545   13 Visit1  778788   13  Visit2      13 Visit3     13 Visit4     13 Visit5     13 Visit6     13 Visit7 454545 1 13 Visit7 778788 1 14  Visit1  545450   14  Visit1 3434454   14  Visit2   545450 1 14  Visit2   3434454   14 Visit3  3434454 1 14  Visit2   3434454       ... View more

Thanks a lot for all your effort.  I added your code snippet in my code.  We are almost there,,,, this code is taking most part of my datafile Except that, the below scenario has to be covered,   data have; infile cards truncover; input PatientID Visit $ Medication reCalc; cards; 1 Visit1 111111 1 Visit2 222222 1 Visit2 33333 1 Visit3 . 1 1 Visit4 888888 12 Visit1 34343 12 Visit2  . 12 Visit2  . 12 Visit2 . 12 Visit4 . 1 12 Visit5 43333 12 Visit6 . 1 ;   Please try this.  When there are many null values, it is nit considering. Please help me with this as well.   ... View more