topic Re: overlapping date observations in SAS Programming

overlapping date observations

terjeph — Thu, 05 Jan 2017 13:27:40 GMT

I've got dates describing periodes (start end) and a variable describing waiting time (wt). However, the dates are partialle overlapping. This is nearly fixed in the attached program but I would like to have latest observation of wt to be placed in correctly. Anyone?

Re: overlapping date observations

Shmuel — Thu, 05 Jan 2017 16:03:33 GMT

You have similar situation as in next post.See solution - it fits your case:

https://communities.sas.com/t5/General-SAS-Programming/Sorting-overlapping-dates-and-address-histories/td-p/315687

Re: overlapping date observations

Daniel-Santos — Thu, 05 Jan 2017 17:20:24 GMT

Hi.

If I got this right, you just need to sort the data correctly and fetch the previous stdate between by groups.

* sort reversing stdate (recent to later);
proc sort data=waits;
by hospid diag descending stdate;

run;

* adjust overlapping between by groups;
data waits2;
set waits;
format stdate enddate date9.;
drop _:;
by hospid diag;

* fetch previous stdate;
_enddate=lag1(stdate);
* skip first by group row, fix overlapping;
if not first.diag then enddate=min(enddate,_enddate-1);

run;

* sort back (later to recent);
proc sort;
by hospid diag stdate;
run

lagN functions will retrieve the previous Nth row value of PDV.

More here: http://support.sas.com/documentation/cdl/en/lrdict/64316/HTML/default/viewer.htm#a000212547.htm

The rest is just pure data step logic.

Hope it helps.

Daniel Santos @ www.cgd.pt

Re: overlapping date observations

terjeph — Thu, 05 Jan 2017 17:07:22 GMT

Thanks! worked well.