Predicting outcomes in HIV-infected veterans: I. Progression to AIDS

This article and the following article (Parts I and II) report the development of two clinical staging systems for HIV-infected individuals. The objective of the research reported here (Part I) was to construct a clinical staging system to predict progression to AIDS. We analyzed data from VA Cooperative Study Number 298, a multicenter, double-blind, randomized trial that compared immediate versus deferred zidovudine therapy in 338 HIV-infected individuals who did not have AIDS at enrollment. Baseline variables were tested in univariate Cox regression for their relationship to progression to AIDS, and those that appeared predictive were examined in multivariable analysis. Based on these analyses, we constructed a new clinical staging system based on CD4+ cell count, age, hemoglobin, oral hairy leukoplakia or oral thrush, and fever. The stages of the system were significant predictors of progression to AIDS (p = 0.0001, log-rank test). In conclusion, simple, valid, clinical staging systems for HIV-infected patients can be constructed using information that is readily available in clinical practice settings. Such systems provide better prognostic distinction than CD4+ cell count alone by taking into account the known prognostic effects of other variables.