Repatead Measures on AIDS Data

Description

Both longitudinal and survival data were collected in a recent clinical trial to compare the efficacy and safety of two antiretroviral drugs in treating patients who had failed or were intolerant of zidovudine (AZT) therapy (Rizopoulos, 2015). In this trial, 467 HIV-infected patients were enrolled and randomly assigned to receive either didanosine (ddI) or zalcitabine (ddC). The number of CD4 cells per cubic millimeter of blood were recorded at study entry, and again at the 2, 6, 12, and 18 month visits.

Usage

data("aids")

Format

A data frame with 1405 observations on the following 12 variables.

patient

patients identifier for 467 patients

Time

time to death or censoring

death

status with 0 denoting censoring and 1 death for patient

CD4

CD4 cells count

obstime

time points at which the CD4 cells count was recorded

drug

a factor with levels ddC (zalcitabine) and ddI (didanosine)

gender

a factor with levels female and male

prevOI

a factor with levels noAIDS (previous opportunistic infection at study entry) and AIDS (no previous infection)

AZT

a factor with levels intolerance (AZT intolerance) and failure (AZT failure)

start

start of time in the interval

stop

end of time in the interval

event

status with 0 denoting censoring and 1 death in the interval

References

Rizopoulos, D. (2015). JM: Joint Modeling of Longitudinal and Survival Data. R package version 1.4-2.

Results