use z:documents/teach/datasets/mri g logldl= log(ldl) g cldl= ldl - 1 g cldlsqr= cldl^2 g cldlcub= cldl^3 egen ldlctg= cut(ldl), at(0,70,100,130,160,400) mkspline sldlA 69 sldlB 99 sldlC 129 sldlD 159 sldlE = ldl ****** *** Problem 1 ****** stset obstime death *** Problem 1a stcox cldl i.ldlctg, robust testparm i.ldlctg* predict hr1a *** Problem 1b stcox cldl cldlsqr, robust predict hr1b *** Problem 1c stcox cldl cldlsqr cldlcub, robust test cldlsqr cldlcub predict hr1c *** Problem 1d stcox cldl sldl*, robust testparm sldl* predict hr1d *** Problem 1e stcox cldl logldl, robust predict hr1e *** Problem 1f scatter hr1a hr1b hr1c hr1d hr1e ldl, ytitle("Fitted Hazard Ratio Estimates") /// xtitle("Serum LDL (mg/dL)") t1title("Fitted Hazard Ratio Estimates Relative to LDL= 1 mg/dL") /// color("black" "blue" "pink" "orange" "green") /// legend(label(1 "Dummy Variables") label(2 "Quadratic") label(3 "Cubic") /// label(4 "Splines") label(5 "Log") ) tabstat hr1a hr1b hr1c hr1d hr1e if ldl==125, stat(mean) replace hr1a= hr1a / .2952228 replace hr1b= hr1b / .1293906 replace hr1c= hr1c / .0797042 replace hr1d= hr1d / .1181797 replace hr1e= hr1e / .0095167 scatter hr1a hr1b hr1c hr1d hr1e ldl, ytitle("Fitted Hazard Ratio Estimates") /// xtitle("Serum LDL (mg/dL)") t1title("Fitted Hazard Ratio Estimates Relative to LDL= 125 mg/dL") /// color("black" "blue" "pink" "orange" "green") /// legend(label(1 "Dummy Variables") label(2 "Quadratic") label(3 "Cubic") /// label(4 "Splines") label(5 "Log") ) drop hr1* sldl* cldl* logldl ****** *** Problem 2 ****** stcox sldl*, robust testparm sldl* predict hr1d ****** *** Problem 3 ****** stcox i.race##c.logldl, robust testparm i.race#c.logldl testparm c.logldl i.race#c.logldl testparm i.race i.race#c.logldl testparm 2.race 2.race#c.logldl ****** *** Problem 4 ****** clear use z:documents/teach/datasets/salary drop if year < 90 drop if startyr < 90 drop if yrdeg < startyr-1 regress salary i.female##c.year, cluster(id) testparm 1.female 1.female#c.year testparm year 1.female#c.year g logslry= log(salary) regress logslry i.female##c.year, cluster(id) eform("GeomMn") testparm 1.female 1.female#c.year testparm year 1.female#c.year regress salary i.female##c.year, robust testparm 1.female 1.female#c.year testparm year 1.female#c.year regress logslry i.female##c.year, robust eform("GeomMn") testparm 1.female 1.female#c.year testparm year 1.female#c.year