R/plasma.R

In nclSLR: The nclSLR package.

#' Blood screening data.
#'
#' The erythrocyte sedimentation rate (ESR) and measurements of two plasma proteins 
#' (fibrinogen and globulin).
#' 
#' @name plasma
#' @docType data
#' @usage data(plasma)
#' @return A data frame with 32 observations on the following 3 variables:
#' \describe{
#' \item{fibrinogen}{The fibrinogen level in the blood.}
#' \item{globulin}{The globulin level in the blood.}
#' \item{ESR}{A factor with two levels representing the erythrocyte sedimentation 
#' rate, either less or greater 20 mm / hour.}}
#' @details
#' The erythrocyte sedimentation rate (ESR) is the rate at which red blood cells 
#' (erythrocytes) settle out of suspension in blood plasma, when measured under 
#' standard conditions. If the ESR increases when the level of certain proteins 
#' in the blood plasma rise in association with conditions such as rheumatic 
#' diseases, chronic infections and malignant diseases, its determination might 
#' be useful in screening blood samples taken form people suspected to being 
#' suffering from one of the conditions mentioned. The absolute value of the ESR 
#' is not of great importance rather it is whether it is less than 20mm/hr since 
#' lower values indicate a healthy individual.
#' 
#' The question of interest is whether there is any association between the 
#' probability of an ESR reading greater than 20mm/hr and the levels of the two 
#' plasma proteins. If there is not then the determination of ESR would not be 
#' useful for diagnostic purposes.
#' @source 
#' D. Collett and A. A. Jemain (1985), Residuals, outliers and influential 
#' observations in regression analysis. \emph{Sains Malaysiana}, \bold{4}, 
#' 493--511.
#' @keywords datasets
#' @examples
#' data(plasma)
#' layout(matrix(1:2, ncol = 2))
#' boxplot(fibrinogen ~ ESR, data = plasma, varwidth = TRUE)
#' boxplot(globulin ~ ESR, data = plasma, varwidth = TRUE)
NULL