forvalues i = 1/80 { gen vcal1_`i' = substr(vcal_1,`i',1) } keep caseid v001 v002 v003 v005 v008 v011 v017 v018 v019 vcal1* reshape long vcal1_, i(caseid) j(i) gen cmc=v017+80-i gen age=int((cmc-v011)/12)