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Create simulated study basics
56 lines (56 loc) · 1.68 KB
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Create simulated study basics
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/*get the study basics*/
program studybasics
/*inputs: totalsize studynum minsize caseprob*/
/*SET SIZE*/
/*total size*/
scalar totalsize=`1'
/*number of studies*/
scalar studynum=`2'
/*variability in study size (meansize automatically computed and from that the maximum - only minimum needs to be inputted - uniform distribution)*/
scalar minsize=`3'
scalar meansize=totalsize/studynum
scalar maxsize=2*meansize-minsize
/*generate uniformly distributed study sizes [minsize-maxsize] - repeat until the last study (not random) is within the desired range*/
scalar bool1=0
while bool1==0 {
scalar tsize=0
forvalues i=1(1)`=studynum-1'{
scalar stsize`i' = minsize+int((maxsize-minsize+1)*runiform())
scalar tsize = tsize + stsize`i'
}
scalar stsize`=studynum'=totalsize-tsize
if stsize`=studynum'>=minsize & stsize`=studynum'<=maxsize {
scalar bool1 = 1
}
}
/*set balanced-unbalanced design - proportion of intervention group*/
scalar caseprob=`4'
forvalues i=1(1)`=studynum'{
scalar stisize`i'=int(caseprob*stsize`i')
scalar stcsize`i'=int((1-caseprob)*stsize`i')
/*add the potential extra randomly if needed*/
if stisize`i'+stcsize`i'<stsize`i' {
if runiform()<=0.5 {
scalar stisize`i'=stisize`i'+1
}
else {
scalar stcsize`i'=stcsize`i'+1
}
}
}
/*start generating the dataset - groups*/
qui clear
qui set obs `=totalsize'
/*generate overall identifier*/
qui egen id = seq()
/*study identifier*/
qui gen studyid=.
qui gen grp=0
scalar tsize=0
forvalues i=1(1)`=studynum'{
qui replace studyid=`i' if id>tsize
/*group identifier allocation*/
qui replace grp=1 if studyid==`i' & id<=tsize+stisize`i'
scalar tsize=tsize+stsize`i'
}
end