EPID 766: Analysis of Longitudinal Data from ... - NCSU Statistics

CHAPTER 1 Epid 766, D. Zhang
title "First stage in two-stage analysis";
proc reg outest=out noprint;
model cholst = year;
by newid;
run;
data out; set out;
b0hat = intercept;
b1hat = year;
keep newid b0hat b1hat;
run;
data main; merge cholst out;
by newid;
if first.newid=1;
run;
title "Summary statistics for intercepts and slopes";
proc means mean stderr var t probt;
var b0hat b1hat;
run;
title "Correlation between intercepts and slopes";
proc corr;
var b0hat b1hat;
run;
Graduate Summer Session in Epidemiology Slide 34