The mortality rate as a function of accumulated deficits in a frailty index.

In a representative Canadian population survey (n=66589) the proportion of accumulated deficits in a frailty index showed a linear relationship with mortality in a log-log plot, such that the mortality rate was a power-law function of the frailty index. Represented in this way, the frailty index readily summarizes individual differences in health status. The exponent and amplitude parameters of the power function are gender specific, reflecting that while, on average, women accumulate more deficits than men of the same age, their risk of mortality is lower. The dependence of the mortality rate on the frailty index points to the merit of the index as a simple and accessible tool for estimating individual risks of mortality.