Notes
Variable créée à partir des variables a8m, a8a, a8nm et a8na
Programme Stata :
gen date1= mdy(a8m,1,a8a)
replace date1= mdy(1,1,a8a) if a8m==.
gen s1 = dateinter - date1
gen s2 = a8nm*30.4
gen s3 = a8na*365.25
capture drop a8_r
egen a8_r= rowtotal(s1 s2 s3)
replace a8_r=. if inlist(a8,7,6)
replace a8_r=. if samplea8==0
replace a8_r= a8_r/365.25