topic Re: flagging dianosis during study period in SAS Programming

flagging dianosis during study period

leahcho — Fri, 03 Nov 2017 14:06:50 GMT

Hi I want to flag diagnosis codes during defined study period

DM dignosis pt ID From_dt To-Dt

1 (yes) 1 2005-04-02 2006-05-20

2(yes) 2 2001-01-01 2001-01-02

Study period index_dt end_dt

2004-04-01 2007-01-10

I want my result to look like;

Pt ID eligible

1 yes

2 no

Thanks

Re: flagging dianosis during study period

RW9 — Fri, 03 Nov 2017 14:23:33 GMT

Post test data in the form of a datastep. I haven't time to type that in or guess what formats etc the table has. So at a rough guess:

proc sql;
  create table WANT as
  select  A.PT_ID,
          case when A.FROM_DT <= B.END_DT and A.TO_DT > B.INDEX_DT then "yes" else "no" end as ELIGIBLE
  from    HAVE1 A
  left join HAVE2 B
  on      1=1;
quit;

You can do the same thing in datastep merge also, basically your merging the dates dataset onto the main one, then doing an if between the two dates.

Re: flagging dianosis during study period

leahcho — Fri, 03 Nov 2017 15:40:34 GMT

Hi,

I need to clarify my initial question. It had mistakes. My variables are all from the same dataset and dates are already SAS dates

DM_diagnosis pt ID from_dt (diag) To_dt (diag) Index_dt end_dt

1 (yes) 1 2005-04-02 2006-05-20 2004-04-01 2007-01-10

1 (yes) 2 2001-01-01 2001-01-02 2003-04-01 2003-12-10

Output

Pt ID eligible

1 yes

2 no

Thanks

Re: flagging dianosis during study period

RW9 — Fri, 03 Nov 2017 16:09:20 GMT

Even simpler then, you just need the if statements:

data want;
  set have;
  if from_dt <= end_dt and to_dt >= index_dt then eligible="yes";
  else eligible="no";
run;

Re: flagging dianosis during study period

ballardw — Fri, 03 Nov 2017 16:22:58 GMT

@leahcho wrote:

Hi,

I need to clarify my initial question. It had mistakes. My variables are all from the same dataset and dates are already SAS dates

So

DM_diagnosis pt ID from_dt (diag)           To_dt   (diag)           Index_dt             end_dt

1 (yes)              1      2005-04-02           2006-05-20                2004-04-01          2007-01-10

1 (yes)              2      2001-01-01          2001-01-02               2003-04-01          2003-12-10

Output

Pt ID   eligible

1          yes

2         no

Thanks

You may need to provide some additional rules. Is it within study period if the from_dt is prior to the index date but the to_dt is in the interval?

If the from_dt is before and To_dt is past the end_dt (the study interval is within the diag interval)

How about the from_dt is in the interval but the to_dt is past the end_dt?

Re: flagging dianosis during study period

leahcho — Fri, 03 Nov 2017 16:34:36 GMT

I want diagnosis interval to fall within study interval

Thanks