|
Chang,
Thanks much for your suggestion, but I have a problem with your code when
checking for 24 continuous months.
Here is the log:
270 data two;
271 n = 0;
272 do until (last.id);
273 set one;
274 by id mon;
275 last = ifn(first.id, ., lag(mon));
276 n = ifn(mon = intnx('mon', last, 1), n+1, 1);
277 end;
278 flag = (&THRESHOLD <= n);
279 keep id flag;
280 run;
NOTE: Missing values were generated as a result of performing an operation
on missing values.
Each place is given by: (Number of times) at (Line):(Column).
2 at 276:19
My code:
data one;
input id mon :anydtdte.;
format mon mmddyys10.;
cards;
1 7/1/2008
1 8/1/2008
1 9/1/2008
1 10/1/2008
1 11/1/2008
1 12/1/2008
1 1/1/2009
1 2/1/2009
1 3/1/2009
1 4/1/2009
1 5/1/2009
1 6/1/2009
1 7/1/2009
1 8/1/2009
1 9/1/2009
1 10/1/2009
1 11/1/2009
1 12/1/2009
1 1/1/2010
1 2/1/2010
1 3/1/2010
1 4/1/2010
2 7/1/2008
2 8/1/2008
2 9/1/2008
2 10/1/2008
2 11/1/2008
2 12/1/2008
2 1/1/2009
2 2/1/2009
2 3/1/2009
2 4/1/2009
2 5/1/2009
2 6/1/2009
2 7/1/2009
2 8/1/2009
2 9/1/2009
2 10/1/2009
2 11/1/2009
2 12/1/2009
2 1/1/2010
2 2/1/2010
2 3/1/2010
2 4/1/2010
2 5/1/2010
2 6/1/2010
;
run;
/* flag if at least 24 continous months */
%let THRESHOLD = 24;
proc sort data=one;
by id mon;
run;
data two;
n = 0;
do until (last.id);
set one;
by id mon;
last = ifn(first.id, ., lag(mon));
n = ifn(mon = intnx('mon', last, 1), n+1, 1);
end;
flag = (&THRESHOLD <= n);
keep id flag;
run;
/* check */
proc print data=two noobs;
run;
What is causing the missing values and how can it be corrected?
Thanks again for your help.
Dave
On Tue, 20 Jul 2010 17:05:21 -0400, Chang Chung
<chang_y_chung@HOTMAIL.COM> wrote:
>On Tue, 20 Jul 2010 16:49:16 -0400, Dave Brewer <david.brewer@UC.EDU>
wrote:
>...
>>I have been trying to come up with code to calculate if a patient has
been
>>enrolled in Medicaid for 12 continuous months, but to no avail.
>...
>>I would like the code to be dynamic; in other words, I might need to
check
>>for 24 continuous months the next time.
>...
>Hi, Dave,
>Here is one way. hth.
>Cheers,
>Chang
>
>/* test data */
>data one;
> input id mon :anydtdte.;
> format mon mmddyys10.;
>cards;
>1 01/01/2009
>1 02/01/2009
>1 03/01/2009
>1 06/01/2009
>1 07/01/2009
>1 08/01/2009
>1 09/01/2009
>1 10/01/2009
>1 11/01/2009
>1 12/01/2009
>1 04/01/2010
>2 05/01/2009
>2 08/01/2009
>2 09/01/2009
>2 10/01/2009
>2 11/01/2009
>2 12/01/2009
>2 01/01/2010
>2 02/01/2010
>2 03/01/2010
>2 04/01/2010
>2 05/01/2010
>2 06/01/2010
>2 07/01/2010
>;
>run;
>
>/* flag if at least 12 continous months */
>%let THRESHOLD = 12;
>
>proc sort data=one;
> by id mon;
>run;
>
>data two;
> n = 0;
> do until (last.id);
> set one;
> by id mon;
> last = ifn(first.id, ., lag(mon));
> n = ifn(mon = intnx('mon', last, 1), n+1, 1);
> end;
> flag = (&THRESHOLD <= n);
> keep id flag;
>run;
>
>/* check */
>proc print data=two noobs;
>run;
>/* on lst
>id flag
> 1 0
> 2 1
>*/
| 
