topic Re: Medication intensification in SAS Programming

Medication intensification

jcooper3 — Mon, 03 Feb 2014 17:50:13 GMT

Hi all-

I have the following dataset:

patient ID drug class quarter 1 quarter2 quarter3...
1 4 0 1 1

1 3 1 0 0

1 7 0 0 0

1 1 0 0 0

The quarters continue over 36 quarters and 0/1 under the quarter columns indicate use of that drug during that quarter.

I'm trying to determine the best way possible to note medication additions? This is a very large dataset (n=~900,000 pts) and I'm applying a rule to the addition- the drug has to show up for a consecutive 2 quarters for the person to be considered a "user"

Do I need to re-structure the data?

Any help would be greatly appreciated- thanks much!

Re: Medication intensification

PGStats — Mon, 03 Feb 2014 18:32:38 GMT

To get the list of first additions, you can use an array, this way:

data have;

input patientID drugClass quarter1-quarter6;

datalines;

1 4 0 1 1 0 1 1

1 3 1 0 0 1 1 0

1 7 0 0 0 0 1 0

1 1 0 0 0 0 0 0

;

data firstAdditions(keep=patientID drugClass addq);

set have;

array q{*} quarter:;

do addQ = 1 to dim(q)-1;

if q{addQ} and q{addQ+1} then do;

output;

leave;

end;

run;

proc print data=firstAdditions noobs; run;

Re: Medication intensification

Haikuo — Mon, 03 Feb 2014 19:13:55 GMT

Another way to identify is to convert them into strings:

data want;

set have;

array qtr quarter:;

if find(cats(of qtr(*)),'11');

run;

Haikuo