cd4                   package:boot                   R Documentation

CD4 Counts for HIV-Positive Patients

Description:

     The 'cd4' data frame has 20 rows and 2 columns.

     CD4 cells are carried in the blood as part of the human immune
     system.  One of the effects of the HIV virus is that these cells
     die.  The count of CD4 cells is used in determining the onset of
     full-blown AIDS in a patient.  In this study of the effectiveness
     of a new anti-viral drug on HIV, 20 HIV-positive patients had
     their CD4 counts recorded and then were put on a course of
     treatment with this drug.  After using the drug for one year,
     their CD4 counts were again recorded. The aim of the experiment
     was to show that patients taking the drug had increased CD4 counts
     which is not generally seen in HIV-positive patients.

Usage:

     data(cd4)

Format:

     This data frame contains the following columns:

     'baseline' The CD4 counts (in 100's) on admission to the trial.

     'oneyear ' The CD4 counts (in 100's) after one year of treatment
          with the new drug.

Source:

     The data were obtained from

     DiCiccio, T.J. and Efron  B. (1996) Bootstrap confidence intervals
     (with  Discussion). _Statistical Science_, *11*, 189-228.

References:

     Davison, A.C. and Hinkley, D.V. (1997)  _Bootstrap Methods and
     Their Application_. Cambridge University Press.

