outdepreg:

#' The multicenter AIDS cohort study
#'
#' CD4 counts collected over time.
#'
#'
#' @format This data frame contains the following columns: \describe{
#' \item{obs}{a numeric vector. Number of observations.} \item{id}{a numeric
#' vector. Id of subject.} \item{visit}{ a numeric vector. Timings of the
#' visits in years.} \item{smoke}{a numeric vector code. 0: non-smoker, 1:
#' smoker.} \item{age}{a numeric vector. Age of the patient at the start of the
#' trial.} \item{cd4}{a numeric vector. CD4 percentage at the current visit.}
#' \item{cd4.prev}{a numeric vector. CD4 level at the preceding visit.}
#' \item{precd4}{a numeric vector. Post-infection CD4 percentage.} \item{lt}{a
#' numeric vector. Gives the starting time for the time-intervals.} \item{rt}{a
#' numeric vector. Gives the stopping time for the time-interval.} }
#' @references Kaslow et al. (1987), The multicenter AIDS cohort study:
#' rational, organisation and selected characteristics of the participants.
#' Am. J. Epidemiology 126, 310--318.
#' @source MACS Public Use Data Set Release PO4 (1984-1991). See reference.
#' @keywords datasets
#' @name cd4
#' @examples
#'
#' data(cd4)
#' names(cd4)
#'
NULL