Re: st: identifying re-operations from a list of operation codes and dates

[Stephen Martin <stephen.martin@york.ac.uk>]

Thanks for this Nick.

First a couple of clarifications:

a) yes, oper_7 corresponds to operdate_7
and
b) each oper_ variable contains a single four digit operation code.

Having reshaped as you suggested I thought I saw where you were
directing me but I tried to sort on op_date by id (to get each
patient's operation codes in chronological order) but sort does not
appear to allow by (am I misunderstanding something here?).

To illustrate the data set, here is the reshaped data for the first
patient.  She has four operation codes and the op_date is an elapsed
date.  The position variable can run from 1 to 24 but I have dropped
values 5 - 24 as these are empty for both op_code and op_date.

id  position  op_code  op_date
1   1            A123     18000
1   2            C567     18000
1   3            X678      18010
1   4            B679      17996

Any further guidance would be most welcome.

Steve


On 06/07/2012, Nick Cox <njcoxstata@gmail.com> wrote:
> Paradoxically, or otherwise, there is a lot of detail to absorb here,
> yet you may be suppressing part of the story to keep it as simple as
> possible. We lose either way.
>
> Assuming that e.g. oper_7 corresponds to operdate_7 then all is not
> lost. But I would first
>
> reshape long oper_ operrate_ , i(id)
>
> and then clean up by renaming, dropping missing, sorting on date.
>
> But although you named these variables, I fear there are others. (In
> which variables are the re-operation codes?)
>
> I fear that's only a start and you may need to report back.
>
> Nick
>
> On Fri, Jul 6, 2012 at 3:22 PM, Stephen Martin
> <stephen.martin@york.ac.uk> wrote:
>
>> I have a dataset for patients admitted to hospital.  Each record
>> includes:
>>
>> a) a patient identifer;
>> b) 24 four digit operation procedure variables (oper_1 - oper_24;
>> these are four digit strings such as A148, C169, etc); and
>> c) 24 date of operation variables (operdate_1 - operdate24).
>>
>> Many of the operation procedure code and date variables are empty.
>> The operation procedure code variables are not necessarily in date
>> order.
>>
>> I have a list (list A) of, say, 20 four digit operation codes that can
>> identify whether a patient received an operation for the condition in
>> which I am interested.
>>
>> I also have a list (list B) of, say, 35 re-operation codes.
>>
>> I would like to identify those patients who had both the operation and
>> the re-operation.
>>
>> However, I cannot solely use lists A and B because some of the same
>> codes appear in both lists, and a re-operation must occur at least one
>> day later than the initial operation.
>>
>> Thus I would like to identify patients who:
>> (a) have an operation code from list A
>> and
>> (b) have an re-operation code from list B
>> and
>> (c) where the date of the re-operation is later than the initial
>> operation.
>>
>> Suggestions on how to do this would be very welcome!
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