A set of utilities for calculating the Deficit (frailty) Index (DI) in gerontological studies.
The deficit index was first proposed by Arnold Mitnitski and Kenneth Rockwood
and represents a proxy measure of aging and also can be served as
a sensitive predictor of survival. For more information, see
(i)"Accumulation of Deficits as a Proxy Measure of Aging"
by Arnold B. Mitnitski et al. (2001),
The Scientific World Journal 1,
library(di) dd <- data.frame(subj=seq(1:100), var1=rbinom(100,1,.5), var2=rbinom(100,1,.5), var3=rbinom(100,1,.5)) ddi <- di(dd, c("var1", "var2", "var3"))
Arnold B. Mitnitski, Alexander J. Mogilner, and Kenneth Rockwood, “Accumulation of Deficits as a Proxy Measure of Aging,” TheScientificWorldJOURNAL, vol. 1, pp. 323-336, 2001. doi:10.1100/tsw.2001.58