topic Study Day Calculation problem in SAS Procedures

Study Day Calculation problem

Almighty — Tue, 22 May 2012 16:25:52 GMT

I am having difficulty in calculating study day, the raw date is like below:

asessmentday Event

05May2012 Screening

12May2012 Dose1

13may2012 sampling

15may2012 analysis

16may2012 result

The output should be looks like below: Study_day = 05May2012 - 12May2012 = -7

Study_day= 13May2012 - 12May2012 = 1

study_day asessmentday Event

-7 05May2012 Screening

1 12May2012 Dose administration

2 13may2012 sampling

3 15may2012 analysis

4 16may2012 result

Please help me with the code.

Thanks

Suresh

Re: Study Day Calculation problem

Almighty — Tue, 22 May 2012 18:28:53 GMT

Can any body reply please

Re: Study Day Calculation problem

Haikuo — Tue, 22 May 2012 18:53:10 GMT

Try this: although I believe you should have the same criteria for both before and after day1. But if not, it can be easily adjusted.

data have;

input asessmentday :date9. Event :$15.;

format asessmentday date9.;

cards;

05May2012 Screening

12May2012 Dose1

13may2012 sampling

15may2012 analysis

16may2012 result

02May2012 Screening

10May2012 Dose1

16may2012 sampling

19may2012 analysis

23may2012 result

;

data want (drop=_:);

length event $15.;

do until (event='result');

set have;

if event='Dose1' then _d=asessmentday;

end;

do until (event='result');

set have;

study_day=asessmentday-_d+1;

output;

end;

run;

proc print;run;

Re: Study Day Calculation problem

Astounding — Tue, 22 May 2012 20:57:07 GMT

Don't you really have data for many patients, and a variable like Patient_ID?

In your example, should May 15 really be study day 3, or should it be study day 4?

The programming can actually be quite simple, but you have to present us with the real problem.