aids: Didanosine versus Zalcitabine in HIV Patients
In JM: Joint Modeling of Longitudinal and Survival Data

aids	R Documentation

Didanosine versus Zalcitabine in HIV Patients

Description

A randomized clinical trial in which both longitudinal and survival data were collected to compare the efficacy and safety of two antiretroviral drugs in treating patients who had failed or were intolerant of zidovudine (AZT) therapy.

Format

A data frame with 1408 observations on the following 9 variables.

patient: patients identifier; in total there are 467 patients.
Time: the time to death or censoring.
death: a numeric vector with 0 denoting censoring and 1 death.
CD4: the CD4 cells count.
obstime: the time points at which the CD4 cells count was recorded.
drug: a factor with levels ddC denoting zalcitabine and ddI denoting didanosine.
gender: a factor with levels female and male.
prevOI: a factor with levels AIDS denoting previous opportunistic infection (AIDS diagnosis) at study entry, and noAIDS denoting no previous infection.
AZT: a factor with levels intolerance and failure denoting AZT intolerance and AZT failure, respectively.

Note

The data frame aids.id contains the first CD4 cell count measurement for each patient. This data frame is used to fit the survival model.

References

Goldman, A., Carlin, B., Crane, L., Launer, C., Korvick, J., Deyton, L. and Abrams, D. (1996) Response of CD4+ and clinical consequences to treatment using ddI or ddC in patients with advanced HIV infection. Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology 11, 161–169.

Guo, X. and Carlin, B. (2004) Separate and joint modeling of longitudinal and event time data using standard computer packages. The American Statistician 58, 16–24.