set more off
clear

/*create blank data set*/
set obs 1000 //creates a blank dataset
gen id=_n //creates id number

/*step 1: set parameters */
*i Specify exposure
gen wflpct=rnormal(50,10)

*ii effect modifier
gen rsupplement=rnormal()
gen supplement=0
replace supplement=1 if wflpct<30 & rsupplement>-1
replace supplement=1 if wflpct>=30 & wflpct<85 & rsupplement>1.5

*iii Outcome prevalence of FEV1pp <50 at 18 years
gen prevFEV1pp_bad=0.75 if wflpct<50 & supplement==0 /* unsupplemented small kids risk of poor lung function */
replace prevFEV1pp_bad=0.5 if wflpct<50 & supplement==1 /* supplemented small kids risk of poor lung function*/
replace prevFEV1pp_bad=0.1 if wflpct>=50 & supplement==0 /*unsupplemented large kids risk of poor lung functin */
replace prevFEV1pp_bad=0.05 if wflpct>=50 & supplement==1 /*supplemented large kids risk for poor lung function */

gen wflsupp=0
replace wflsupp=1 if wflpct<50 & supplement==1
replace wflsupp=2 if wflpct>=50 & supplement==0
replace wflsupp=3 if wflpct>=50 & supplement==1

tabstat id, by (wflsupp) s(p75 p50 p10 p5)

gen FEV1pp_bad=0
replace FEV1pp_bad=1 if id<745 & wflsupp==0
replace FEV1pp_bad=1 if id<556 & wflsupp==1
replace FEV1pp_bad=1 if id<94 & wflsupp==2
replace FEV1pp_bad=1 if id<89 & wflsupp==3


save "/Users/mollyrdju/Box Sync/MASTERS/Spring 2016/Methods in Chronic Disease Epi/week 10/HW data.dta", replace

set more off
clear

/*create blank data set*/
set obs 1000 //creates a blank dataset
gen id=_n //creates id number

/*step 1: set parameters */
*i Specify exposure
gen wflpct=rnormal(50,10)

*ii effect modifier
gen rsupplement=rnormal()
gen supplement=0
replace supplement=1 if wflpct<30 & rsupplement>-1
replace supplement=1 if wflpct>=30 & wflpct<85 & rsupplement>1.5

*iii Outcome prevalence of FEV1pp <50 at 18 years
gen prevFEV1pp_bad=0.1 if wflpct<50 & supplement==0 /* unsupplemented small kids risk of poor lung function */
replace prevFEV1pp_bad=0.05 if wflpct<50 & supplement==1 /* supplemented small kids risk of poor lung function*/
replace prevFEV1pp_bad=0.1 if wflpct>=50 & supplement==0 /*unsupplemented large kids risk of poor lung functin */
replace prevFEV1pp_bad=0.05 if wflpct>=50 & supplement==1 /*supplemented large kids risk for poor lung function */

gen wflsupp=0
replace wflsupp=1 if wflpct<50 & supplement==1
replace wflsupp=2 if wflpct>=50 & supplement==0
replace wflsupp=3 if wflpct>=50 & supplement==1

tabstat id, by (wflsupp) s(p75 p50 p10 p5)

gen FEV1pp_bad=0
replace FEV1pp_bad=1 if id<107 & wflsupp==0
replace FEV1pp_bad=1 if id<61 & wflsupp==1
replace FEV1pp_bad=1 if id<94 & wflsupp==2
replace FEV1pp_bad=1 if id<47 & wflsupp==3

save "/Users/mollyrdju/Box Sync/MASTERS/Spring 2016/Methods in Chronic Disease Epi/week 10/HW data2.dta", replace