Chronological age

Chronological age is the time elapsed since a person's birth, usually measured in years. It is the standard reference variable in demography, medicine and epidemiology and remains one of the strongest single predictors of mortality and many age-associated conditions. Unlike biological age, chronological age does not capture variation in physiological decline between individuals; two people of the same chronological age may differ markedly in functional capacity, disease risk and remaining healthspan, and depending on cohort and endpoint other measures can match or exceed its predictive value.