If you create a pseudopatient who has -filldate- for
the start of every quarter in your study period and
then -tsset- and -tsfill- every patient will have
a grid of quarters within their observations.
This is only part of the problem but may help.
Nick
[email protected]
Jeph Herrin
> I'm hoping for some insight into a solution to the following
> programming problem.
>
> For 170k patients (ID), I have the dates they filled prescriptions
> (-filldate-) and the number of -days- each prescription covers (eg,
> the number of daily pills):
>
> ID filldate days
> 1 10JAN01 30
> 1 20FEB01 14
> 1 03MAR01 45
> 1 05MAY01 30
> .
> .
> 2 etc
> 2
> 2
> .
> .
> .
>
> The problem is that I need to figure how many total -days- they
> are covered out of each 90 day quarter. So in the above, the first
> patient starts on 10JAN01, so the first 90 day quarter ends on
> 10APR01. That means I need to break the 3rd record (03MAR01) into
> two records, 38 days for the first quarter and 7 days for the second
> quarter. I have to do this for all four 90 day quarters starting
> 10JAN01, and I have to do for every patient (and they all have
> different start dates).
>
> What I'd like to do is insert a new record at the start of each
> quarter UNLESS they already have a record for that date. Then
> the last -filldate- for each quarter would be split to form the
> new record.
>
> However, all of my attempts end up looking hopelessly complex
> and hence unreliable, and as I so often discover elegant solutions
> on this list I thought I'd fish for one here. Any ideas would
> be welcome.
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