Abstract | BACKGROUND:
Zidovudine therapy improves survival in advanced human immunodeficiency virus ( HIV) infection and delays progression from earlier stages to advanced stage of HIV disease. The duration of the benefit of zidovudine therapy, however, may be limited. OBJECTIVE: To quantitate the duration of the survival benefit of zidovudine therapy in a heterogeneous patient population receiving care for HIV infection in an urban clinic. METHODS: We analyzed data from 393 HIV-infected patients with CD4+ cell counts of 0.5 x 10(9)/L (500 cells/microliter.) or less who first presented for care at The Johns Hopkins HIV Clinic, Baltimore, Md, from July 1989 through December 1993. Follow-up extended to a maximum of 3 years (median, 2 years). Survival probabilities in patients who received and who did not receive zidovudine therapy were analyzed by Kaplan-Meier methods and by multivariate Cox proportional hazards regression analysis adjusting for both time-dependent and fixed prognostic covariates. RESULTS: Adjusting for baseline differences in CD4+ cell count, clinical stage of HIV disease, and prophylaxis for Pneumocystis carinii pneumonia, Cox regression analysis showed a significant effect of zidovudine compared with no treatment on the risk of dying during the first year of therapy (relative hazard for death, 0.32; 95% confidence interval [CI], 0.18 to 0.59). However, analysis of the time-dependent effect of zidovudine therapy showed that there was a diminishing relative hazard between treatment and no treatment of 0.75 (95% CI, 0.45 to 1.26) at 1 to 2 years of therapy and a relative hazard of 1.61 beyond 2 years (95% CI, 0.70 to 3.71). CONCLUSION: The survival advantage of zidovudine therapy is time dependent, lasting between 1 and 2 years in patients with CD4+ cell counts of 0.5 x 10(9)/L or less. Alternative antiretroviral treatment may be indicated at that time.
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Authors | R D Moore, J C Keruly, R E Chaisson |
Journal | Archives of internal medicine
(Arch Intern Med)
Vol. 156
Issue 10
Pg. 1073-7
(May 27 1996)
ISSN: 0003-9926 [Print] United States |
PMID | 8638994
(Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Antiviral Agents
- Zidovudine
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Topics |
- Adult
- Antiviral Agents
(therapeutic use)
- Female
- HIV Infections
(drug therapy, mortality)
- Humans
- Male
- Middle Aged
- Proportional Hazards Models
- Survival Rate
- Time Factors
- Treatment Outcome
- Zidovudine
(therapeutic use)
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