st: Data management for drug study

["Pooja Desai" <desai.pooja87@gmail.com>]

Hello All,
I have a dataset which is as follows:
ID	psy_vst	rx	drug	days	disp_date	
123	     .		1	12	90	15141
123	      1		 .	12	30	15153
123	      1		 .	12	30	15195
123	      1		 .	12	30	15225
123	      1		 .	3	2	15227 
123	      1		 .	12	30	15266
123	     .		1	1	60	15271
123	      1		 .	7	30	15278
123	      1		 .	7	30	15311
123	      1		 .	7	30	15341

ID is the patient ID number, psy_vst =1 indicates that the event was a
physician visit, rx=1 indicates that the event was a pharmacy visit, each
drug is represented by a particular number so the same number under the drug
column indicates the same drug,, a different number indicates a different
drug, the days variable indicates the days supply for the particular drug
and the disp_date indicates the day the drug was given. I want to delete
(and create a new dataset of these deleted values) when there is a physician
visit associated with the same drug days supply +30 days after the dispense
date of the drug from the pharmacy. So in the above example for patient 123,
rows 2,3,4 should be deleted from this dataset (and put into a new one) and
rows 1, 5, 6, 7, 8, 9, 10 will remain in the dataset as the visits in rows
8, 9, 10 are not for the same drug that was dispensed in the pharmacy on
date 15271.

Please could somebody help me write such a code?
Thanks a lot!
Pooja Desai


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