This function is part of the cluster bootstrap optimism correction procedure described in Signorelli et al. (2020, in review). Note that the function does not perform the random sampling, but it extracts the correct records from a dataframe, given the ids of the sampled clusters (subjects)
draw_cluster_bootstrap(df, idvar, boot.ids)
a data frame in long format
name of the subject id in df
(it should be a
numeric id that ranges from 1 to n, without skipping values)
identifiers of the subjects to be sampled
A data frame containing the bootstrapped observations
Signorelli, M., Spitali, P., Al-Khalili Szigyarto, C, The MARK-MD Consortium, Tsonaka, R. (2021). Penalized regression calibration: a method for the prediction of survival outcomes using complex longitudinal and high-dimensional data. Statistics in Medicine, 40 (27), 6178-6196. DOI: 10.1002/sim.9178