## Create study day variable for multiple per day encounters

Solved
Occasional Contributor
Posts: 9

# Create study day variable for multiple per day encounters

Hi,

I am trying to create a study day variable for patients that have multiple encounters per day.

For example:

ID    Date        Study Day (want to create this)

12   6/20/14      1

12   6/20/14      1

12   6/20/14      1

12   6/20/14      1

12   6/22/14      2

12   6/26/14      3

13   6/20/14      1

Any thoughts?

Thanks!

Accepted Solutions
Solution
‎08-07-2015 12:54 AM
Regular Contributor
Posts: 249

## Re: Create study day variable for multiple per day encounters

Hi, perhaps you could try this?

data have;

input ID DATE MMDDYY10.;

datalines;

12   6/20/14

12   6/20/14

12   6/20/14

12   6/20/14

12   6/22/14

12   6/26/14

13   6/20/14

;

run;

proc sort data=have; by ID Date; run;

data want;

set have;

by ID Date;

if first.id then studyday=.;

if not missing(date) then do;

if date ne lag(date) then studyday+1;

end;

run;

proc print noobs; format date ddmmyy10.; run;

All Replies
Solution
‎08-07-2015 12:54 AM
Regular Contributor
Posts: 249

## Re: Create study day variable for multiple per day encounters

Hi, perhaps you could try this?

data have;

input ID DATE MMDDYY10.;

datalines;

12   6/20/14

12   6/20/14

12   6/20/14

12   6/20/14

12   6/22/14

12   6/26/14

13   6/20/14

;

run;

proc sort data=have; by ID Date; run;

data want;

set have;

by ID Date;

if first.id then studyday=.;

if not missing(date) then do;

if date ne lag(date) then studyday+1;

end;

run;

proc print noobs; format date ddmmyy10.; run;

Super User
Posts: 23,773

## Re: Create study day variable for multiple per day encounters

Data want;

set have;

by id date;

retain studyday;

if first.id the studyday=0;

if first.date then studyday+1;

run;

Occasional Contributor
Posts: 9

## Re: Create study day variable for multiple per day encounters

Thank you both so much! The solutions worked perfectly!

🔒 This topic is solved and locked.

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