Date:         Sun, 20 May 2007 10:39:42 -0400
Reply-To:     "data _null_;" <datanull@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "data _null_;" <datanull@GMAIL.COM>
Subject:      Re: how to grab the Subsequent record(a better approach) ?
Comments: To: SAS_learner <proccontents@gmail.com>
In-Reply-To:  <c2192a610705200724y7fcf9b7br4930b2210d17675a@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Post some example data.  And desired output.

On 5/20/07, SAS_learner <proccontents@gmail.com> wrote:
> Hello all,
>
> After seeing Richard's macro on  lag function I thought some body would
> have  a better Idea of doing this one
>
> What I was doing other day is not entirely a Lag but some thing (reverse) of
> that kind . Here is what I wanted to accomplished other day
>
> "If there is a record where DOSEDT and PREDOSE are both non-,missing prior
> to first dose date  (that is, DOSEDT < FDDT), then for the last DOSEDT prior
> to FDDT
> CORTDUR =  ( *DOSEDT (subsequent record)* - FDDT)"
>
>
> For grabing the Subsequent record for a same patient I had  to write this
> way. I know it is pretty ineffient way but I could not think of better way.
> Here is way I tried to achive it does anybody has better way of doing it.
>
> data aa_1  ;
>    set a_temp ;
> by pt ;
> if dosedt >= fddt then dosedt3 = dosedt ;
> if dosedt >= fddt then cortdur_fir_rec  = dosedt3 - fddt ;
> if not first.pt  then count = 1  ;
> if count = 1 ;
> keep pt cortdur_fir_rec  ;
> format dosedt3 date9. ;
> run;
>
> data aa_2  ;
>    set aa_1  ;
> by pt ;
> if /*first.pt  and */ cortdur_fir_rec = . then delete ;
> run;
>
> data aa_2  ;
>    set aa_2  ;
> by pt ;
> if first.pt ;
> run;
> data aa_l1 ;
>    set a_temp ;
> by pt ;
> if dosedt < fddt ;
> run;
>
> data aa_l1 ;
>   set aa_l1 ;
> by pt ;
> if last.pt ;
> run;
>
> proc sort data = aa_l1 ;
> by pt ;
> run;
>
> data aa_2 ;
>  merge aa_2  aa_l1 ;
> by pt ;
> if cortdur= . then cortdur = cortdur_fir_rec ;
> run;
>
> proc sort data = aa_2 ;
> by pt dosedt ;
> run;
>
> proc sort data = a_temp ;
> by pt dosedt ;
> run;
>
> data a_temp ;
>    merge a_temp(In= a) aa_2 ;
> by pt dosedt ;
> retain cortdur ;
> if a ;
> if cortdur= . then cortdur = cortdur_fir_rec ;
> if  first.pt and dosedt  = . then cortdur = .;
> drop cortdur_fir_rec;
> run;
>
> proc sort data = v_predose  ;
> by pt   dosedt  ;
> run;
>
> proc sort data = a_temp nodupkey ;
> by pt dosedt ;
> run;
>
> data  v_cortdur;
>    merge v_predose  (in = a )
>          a_temp (keep = pt cortdur  dosedt)
> ;
> by pt dosedt  ;
> if a ;
> run;
>
> proc sort data = v_cortdur ;
> by pt dosedt  ;
> run;
>
> thanks for advice .
>