plasmaR Documentation

Blood Screening Data


The erythrocyte sedimentation rate and measurements of two plasma proteins (fibrinogen and globulin).




A data frame with 32 observations on the following 3 variables.


the fibrinogen level in the blood.


the globulin level in the blood.


the erythrocyte sedimentation rate, either less or greater 20 mm / hour.


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.


D. Collett and A. A. Jemain (1985), Residuals, outliers and influential observations in regression analysis. Sains Malaysiana, 4, 493–511.


  data("plasma", package = "HSAUR")
  layout(matrix(1:2, ncol = 2))
  boxplot(fibrinogen ~ ESR, data = plasma, varwidth = TRUE)
  boxplot(globulin ~ ESR, data = plasma, varwidth = TRUE)