topic Re: Flagging a subject based on visit and it's corresponding dates in SAS Procedures

Flagging a subject based on visit and it's corresponding dates

tad — Fri, 23 Aug 2013 23:10:38 GMT

Hello

Can someone help me in tacking the below and assigning them the flag.

Below is are unique records, I want to flag and increment if they fall under same visit and id, and reflag if not same visit

id date visit output

1 2001-02-21 3 --------------->flag =1

1 2001-02-22 3 --------------->flag =2

2 2002-02-26 9 --------------->flag =1

3 2002-12-13 2 --------------->flag =1

3 2002-12-29 9 --------------->flag =1

4 2004-12-13 7 ---------------->flag =1

4 2004-12-14 7 ----------------->flag =2

4 2005-01-06 24 ------------------>flag =1

4 2005-01-07 24 ------------------>flag =2

For above:

data test;

infile datalines dsd;

input id 1-2 date $3-12 visit 14 ;

datalines;

1 2001-02-21 3

1 2001-02-22 3

2 2002-02-26 9

3 2002-12-13 2

3 2002-12-29 9

4 2004-12-13 7

4 2004-12-14 7

4 2005-01-06 24

4 2005-01-07 24

;

run;

Criteria here

a)for first record same id, visit assign flag=1, when the visit is same for the same id, but the date change than increase the flag by 1.

b) when the first id and and second id observation is same, the visit is different and they are the first record for the the id assign flag to 1.

3) over all id falls in the same visit but changes can be seen on the data increment

Re: Flagging a subject based on visit and it's corresponding dates

Reeza — Fri, 23 Aug 2013 23:33:14 GMT

See the second example here:

SAS FAQ: How can I create an enumeration variable by groups?

Re: Flagging a subject based on visit and it's corresponding dates

tad — Sat, 24 Aug 2013 00:13:43 GMT

Above will not solve the problem , it will assign all the flag to 1

Re: Flagging a subject based on visit and it's corresponding dates

PGStats — Sat, 24 Aug 2013 01:07:01 GMT

If I understand correctly, if a subject had the same visit and date you wouldn't want output to be increased by one. You could do this:

proc sort data=test; by id visit date; run;

data testOut;
set test;
by id visit date;
if first.visit

then output = 1;
else output + first.date;
run;

proc print data=testOut noobs; run;

Re: Flagging a subject based on visit and it's corresponding dates

PGStats — Sat, 24 Aug 2013 01:29:58 GMT

I just noticed something in that second idre example: the statement

if first.class or first.gender then count = 1;

should be simply

if first.gender then count = 1;

since first.class inplies first.gender when data is sorted by class gender. The result is the same of course, except for the poor student trying to learn about the workings of first. and last.

Re: Flagging a subject based on visit and it's corresponding dates

Fugue — Sat, 24 Aug 2013 01:56:26 GMT

data test;
infile datalines dlm=' ' dsd;
format date date9.;
input id date :yymmdd10. visit ;
datalines;
1 2001-02-21 3
1 2001-02-22 3
2 2002-02-26 9
3 2002-12-13 2
3 2002-12-29 9
4 2004-12-13 7
4 2004-12-14 7
4 2005-01-06 24
4 2005-01-07 24
;
;;;;

/* do a precautionary sort */

proc sort data=test;
by id date visit;

/* process and set flag */

Data want ;
set test;
drop last_id last_visit ;
by id date visit;
last_id = lag1(id);
last_visit = lag1(visit);
if last_id = . then flag = 1;
else if id ^= last_id then flag = 1;
else if visit ^= last_visit then flag = 1 ;
else flag + 1 ;
run ;

Re: Flagging a subject based on visit and it's corresponding dates

Fugue — Sat, 24 Aug 2013 01:59:30 GMT

Your solution is simpler and far more elegant than the one I posted.

Re: Flagging a subject based on visit and it's corresponding dates

Pallav — Sat, 24 Aug 2013 05:17:16 GMT

This might be useful

proc sort data = test;

by id visit;

run;

data new;

set test;

by id visit;

if first.visit then flag=0;

flag +1;

Run;

proc print;

run;

Re: Flagging a subject based on visit and it's corresponding dates

UrvishShah — Mon, 26 Aug 2013 07:30:13 GMT

data want;

set have;

by id visit;

if (first.id or first.visit) NE (last.id or last.visit) then flag + 1;

if first.id or first.visit then flag = 1;

run;

-Urvish

Re: Flagging a subject based on visit and it's corresponding dates

tad — Wed, 28 Aug 2013 18:48:11 GMT

Orignial questions was answered but now i would like to add a twist here and introduce a new variable:

id date visit output

1 2001-02-21 3 --------------->flag =1

1 2001-02-22 3 --------------->flag =2

2 2002-02-26 9 --------------->flag =1

3 2002-12-13 2 --------------->flag =1

3 2002-12-29 9 --------------->flag =1

4 2004-12-13 7 ---------------->flag =1

4 2004-12-14 7 ----------------->flag =2

4 2005-01-06 24 ------------------>flag =1

4 2005-01-07 24 ------------------>flag =2

2) New variable introduced here test, so now here, for the same id, different date, same visit but same test would like to increment the flag, otherwise keep as flag 1

id date visit test output

1 2001-02-21 3 a--------------->flag =1

1 2001-02-22 3 a--------------->flag =2

2 2002-02-26 9 a --------------->flag =1

3 2002-12-13 2 a--------------->flag =1

3 2002-12-29 9 a--------------->flag =1

4 2004-12-13 7 a---------------->flag =1

4 2004-12-14 7 b----------------->flag =1

4 2005-01-06 24 a ----------------->flag =1

4 2005-01-07 24 a------------------>flag =2

Re: Flagging a subject based on visit and it's corresponding dates

Reeza — Wed, 28 Aug 2013 18:53:59 GMT

Play around with the by variable.

You probably want by id test date visit or something like that.