You're right, @Ksharp, I tried to simplify as much as possible the input sample and on the way I lost some of its features. Let me introduce a new variable called "withdrawn" which turns to Y if the patient is withdrawn from the study before completing the 4 scheduled visits (0, 1, 2, 3). In that case, the dose value should remain missing for visits to which the patient did not attend. Imagine this modified sample data set on which patients 003 and 004 have an early termination: data sample_data;
infile datalines delimiter=',';
input pt $ visit dose samedose $ withdrawn $;
datalines;
001,0,7.4, ,
001,1,.,Y,
001,2,.,Y,
001,3,.,Y,
002,0,3.7, ,
002,1,2.3,N,
002,2,.,Y,
002,3,.,Y,
003,0,5.4, ,
003,1,.,Y,
003,2,2.7,N,
003,3,., ,Y
004,0,5.4, ,
004,1,3.2,N,
004,2,., ,Y
004,3,., ,Y
;
run; In this case when I run your code I obtain this result on which I have highlighted the unwanted results: Could your code be modified to include this? Thanks for your patience!
... View more