# Spread duration and spread risk for a T bill

How is the spread duration/ spread DV01 for a T bill computed. For a bond paying fixed coupons, the spread DV01 is generally taken to be the yield DV01 (yield sensitivity). But the bond equivalent yield computation for T bills changes on the basis of time to maturity of the T bill (less than 182 days and greater than 182 days). So, is an alternative approach like the OAS model to be used?