Sandy Keith was awarded the Reversal Prize on November 9, 2004 for the husbandry which enabled Charlie to live 1551 days.
As a prelude to the Rejuvenation Prize which employs active technologies to intervene in the aging process, the Reversal Prize sets a benchmark against which the techniques of competitors can be measured for effectiveness in extending the life span of mus musculus.
Reversal Prize (RP): details (since superseded by The Rejuvenation Prize)
The specific purpose of the Reversal Prize is to encourage people to develop effective late-onset life-extension interventions that will be beneficial to the elderly. We are doing this by giving extra credit to interventions that are initiated late in the lifespan. We do this by calculating a nominal "age" using a very simple formula:
in computing the "age" achieved by a mouse whose treatment started only after some age,
the period before treatment began counts double.
In other words:
Age at which treatment begins: X days
So, a treatment that starts at birth translates to an "age" equal to the mouse's actual age at death, but a treatment that starts at one year of age translates into a nominal "age" one year greater than the mouse's actual age at death, because that first year counts as two years. The extreme case is a mouse that gets no treatment at all: its "age" for RP purposes is twice its actual age at death.
Thus, for example, if a treatment is begun at 900 days, and the treated animals live to 1500 days on average, the nominal age achieved is 2400 days. If the same age (1500 days) were subsequently achieved with an intervention begun at 1000 days of age, the nominal age achieved would be 2500 days. The winner would thus receive 1/25 of the RP fund.
It is worth noting that a mouse can become the record-holder for the Reversal Prize but be overtaken by another mouse before it dies!