topic Re: Adding prefix to the visit based on previous or upcoming visits in SAS Data Management

Adding prefix to the visit based on previous or upcoming visits

pavan1 — Wed, 09 May 2018 16:58:08 GMT

Hello Folks,

I have a typical situation here to handle.

Client gave me several visits and wanted to modify(adding prefix to unscheduled visits) the visits based on the previous or next visits, the problem here is we dont even know when the unscheduled visit comes.

Here is the snapshot of the scenario.

Kindly, help me with this

subject   visit       Expected Visit
101   baseline   baseline
101   unscheduled 01   MTN Unscheduled 01
101   unscheduled 02   MTN Unscheduled 02
101   unscheduled 03   MTN Unscheduled 03
101   MTN week 07        MTN week 07
101   MTN WEEK 13      MTN WEEK 13
101   REI baseline        REI baseline
101   REI WEEK 07             REI WEEK 07
101   UNSCHEDULED 01   REI UNSCHEDULED 01
101   UNSCHEDULED 02   REI UNSCHEDULED 02
103   REI WEEK 13            REI WEEK 13

Re: Adding prefix to the visit based on previous or upcoming visits

pavan1 — Wed, 09 May 2018 16:59:17 GMT

sorry typo, last visit is also of the same subject 101

Re: Adding prefix to the visit based on previous or upcoming visits

TomKari — Wed, 09 May 2018 18:22:58 GMT

Well, I had to make a few assumptions about your desired logic, but here's a program that creates your desired output from your input.

Hope it helps!

Tom

data Inter01;
set Have;
SeqNo = _n_;
run;

data Inter02;
length ExpectedVisit $20 OldPrefix $20 CurrentPrefix $20 FirstWord $20;
retain OldPrefix;
set Inter01;
by Subject;
if first.Subject then OldPrefix = " ";
FirstWord = scan(Visit, 1);
if lowcase(FirstWord) ^= "unscheduled" & lowcase(FirstWord) ^= "baseline"
then do;
OldPrefix = FirstWord;
ExpectedVisit = Visit;
end;
else if CurrentPrefix = "" & OldPrefix ^= ""
then do;
CurrentPrefix = OldPrefix;
if lowcase(FirstWord) = "unscheduled"
then ExpectedVisit = catx(" ", CurrentPrefix, Visit);
else ExpectedVisit = Visit;
end;
drop OldPrefix;
run;

proc sort data=Inter02 out=Inter03;
by descending SeqNo;
run;

data Inter04;
length ExpectedVisit $20 OldPrefix $20 CurrentPrefix $20 FirstWord $20;
retain OldPrefix;
set Inter03;
by notsorted Subject;
if first.Subject then OldPrefix = " ";
FirstWord = scan(Visit, 1);
if lowcase(FirstWord) ^= "unscheduled" & lowcase(FirstWord) ^= "baseline"
then do;
OldPrefix = FirstWord;
ExpectedVisit = Visit;
end;
else if CurrentPrefix = "" & OldPrefix ^= ""
then do;
CurrentPrefix = OldPrefix;
if lowcase(FirstWord) = "unscheduled"
then ExpectedVisit = catx(" ", CurrentPrefix, Visit);
else ExpectedVisit = Visit;
end;
run;

proc sql noprint;
create table Want as
select Subject, Visit, ExpectedVisit
from Inter04
order by SeqNo;
quit;

Re: Adding prefix to the visit based on previous or upcoming visits

pavan1 — Wed, 16 May 2018 09:39:51 GMT

Thank you so much Tom its perfectly working...!!!!