The global burden of disease (GBD) 2001–2002 study counted disability adjusted life years equally for all ages, but the GBD 1990 and GBD 2004 studies used the formulaformula_2 where formula_3 is the age at which the year is lived and formula_4 is the value assigned to it relative to an average value of 1.
Tehtanje po starosti pomeni, da je izguba DALY (breme bolezni) večja pri osebi, ki je pri starosti 30 let doživela deset let invalidnosti, kot pri osebi, ki je zaradi iste bolezni ali poškodbe onesposobljena za isto obdobje desetih let pri starosti 70.