R/cotinine.R

In tlm: Effects under Linear, Logistic and Poisson Regression Models with Transformed Variables

#' Birth Weight and Cord Serum Cotinine
#'
#' @description Simulated data for birth weight and cord serum cotinine levels in
#'  351 newborns.
#'
#' @format A \code{data.frame} with 351 observations on the following 4 variables:
#' \describe{
#' \item{cotinine}{cord serum cotinine level in the mother (ng/ml).}
#' \item{logcotinine}{logarithm of \code{cotinine}.}
#' \item{weight}{birth weight (g).}
#' \item{underweight}{a factor with levels \code{no} and \code{yes}, indicating
#'  underweight (\code{weight} < 2500 g).}
#' }
#'
#' @details Data were simulated to emulate true data pattern observed in a real
#'  study (see References).
#'
#' @source See References.
#'
#' @references Pichini S \emph{et al}. Cord serum cotinine as a biomarker of fetal
#'  exposure to cigarette smoke at the end of pregnancy. \emph{Environmental Health
#'  Perspectives}. 2000;108(11):1079-1083.
#' @examples
#' data(cotinine)
#' par(las = 1, mfrow = c(2, 2))
#' with(cotinine, plot(cotinine, weight))
#' with(cotinine, plot(logcotinine, weight))
#' with(cotinine, boxplot(cotinine ~ underweight))
#' with(cotinine, boxplot(logcotinine ~ underweight))
#' @keywords datasets
"cotinine"