I have 100 patients in my dataset. We collected cholesterol level at 3 time points during their visits to the hospital (visit=1, 2, 3). I would like to get the differences of cholesterol (1) between visit 1 and visit 2, and (2) between visit 3 and visit 1.
data looks like this:
ID Visit Cholesterol level
001 1 100
001 2 120
001 3 130
002 1 200
002 2 220
002 3 250
003 1 80
003 2 90
003 3 85
How to I get Cholesterol_diff1 and Cholesterol_diff2?
Cholesterol_diff1 = cholesterol2-chlesterol1;
Cholesterol_diff2 = cholesterol3-chlesterol1;
Thank you in advance!
Look at the DIF<n>() function which can calculate multiple DIF values.
ie
data class;
set sashelp.class;
x =dif(age);
y=dif2(age);
run;
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