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# How To Create Repeated Measure Data Generation

Hello,

I’m a graduate student in bio-statistics and I need your help very much on a SAS syntax explanied below. I really appreciate if you could help/guide me on this request.

I’m trying to create a syntax on Covariance Structures in Repeated Measures Analyses (Unstructured General AR (1) Compound Symetry). In the syntax, I have been trying to write codes that generates repeated data with a normal distribution and with correlation between measurements of each record (patient i.e. 201, 202, 203, 204 in the example below).

The data structure that I’m using is;

data fev1 ;
input PATIENT BASEFEV1 FEV11H FEV12H FEV13H FEV14H FEV15H FEV16H FEV17H FEV18H DRUG \$;
drop fev11h fev12h fev13h fev14h fev15h fev16h fev17h fev18h;
hour=1; fev1=fev11h; output;
hour=2; fev1=fev12h; output;
hour=3; fev1=fev13h; output;
hour=4; fev1=fev14h; output;
hour=5; fev1=fev15h; output;
hour=6; fev1=fev16h; output;
hour=7; fev1=fev17h; output;
hour=8; fev1=fev18h; output;
cards;
201 2.46 2.68 2.76 2.50 2.30 2.14 2.40 2.33 2.20 a
202 3.50 3.95 3.65 2.93 2.53 3.04 3.37 3.14 2.62 a
203 1.96 2.28 2.34 2.29 2.43 2.06 2.18 2.28 2.29 a
204 3.44 4.08 3.87 3.79 3.30 3.80 3.24 2.98 2.91 a
;
proc mixed data=fev1;
class drug patient hour;
model fev1=drug hour drug*hour;
repeated hour / sub=patient(drug) type=un r rcorr;
run;

By the example of main data structure above I want to obtain from syntax with given properties (normal distribution and correlation between data times for each person).

Again, I appreciate your assitance and guıadince on how to find instruction to creat this syntax.