deff(y, cluster)
n
(total number of non-missing observations),
clusters
(number of clusters after deleting missing data),
rho
(intra-cluster correlation), and
deff
(design effect).
Frank Harrell
Department of Biostatistics
Vanderbilt University
f.harrell@vanderbilt.edu
set.seed(1) blood.pressure <- rnorm(1000, 120, 15) clinic <- sample(letters, 1000, replace=TRUE) deff(blood.pressure, clinic)