data a;
input PT$ DOB$ 12.;
label PT="Patient number";
label DOB="Date of birth";
label ICDT="Date of informed consent";
cards;
001 28/FEB/1929
003 06/OCT/1947
002 27/APR/1950
004 21/SEP/1960
;
run;

data b;
input PT$ ICDT$ 12.;
label PT="Patient number";
label DOB="Date of birth";
label ICDT="Date of informed consent";
cards;
001 13/JAN/2010
005 08/MAY/2010
003 25/JUL/2010
;
run;
如何用input来计算年龄，用（ICDT-DOB）/365.25