Life expectancy of patients with newly-diagnosed HIV infection in the era of highly active antiretroviral therapy
From the Departments of 1Internal Medicine and 2Medical Research, National Taiwan University Hospital, Taipei, 3College of Public Health, National Taiwan University, Taipei, 4Department of Health, Executive Yuan, 5Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, 6Taipei Municipal Venereal Disease Control Institute, Taipei and 7Institute of Statistical Science, Academia Sinica, Taipei, Taiwan
Address correspondence to Professor J.D. Wang, Department of Internal Medicine, National Taiwan University Hospital, No.7. Chung San South Road, Taipei, Taiwan. email: jdwang{at}ha.mc.ntu.edu.tw
Received 10 June 2006 and in revised form 23 October 2006
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Abstract |
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Background: Limited data are available on the life expectancy of patients with newly-diagnosed HIV infection in the era of highly active antiretroviral therapy (HAART).
Aim: To provide such an estimate using a semi-parametric projection.
Design: Statistical analysis.
Methods: Follow-up data for patients newly diagnosed with HIV infection in Taiwan (HIV/AIDS Cohort) from 1 May 1997 to 30 April 2003 (n = 3351, only 1% are injecting drug users) were analysed using the Kaplan-Meier method. The survival function for an age- and gender-matched reference population was generated by the Monte Carlo method from the life-table of the general population. A constant excess hazard model was used to project long-term survival of HIV-infected patients, with linear extrapolation of a logit-transformed curve of survival ratio between HIV-infected patients and the reference population.
Results: The 5-year survival rate was 58% in patients who had already developed AIDS at diagnosis (AIDS group), and 89% in those who had not (non-AIDS group). Extrapolation yielded an expected mean survival time of 10.6 years after diagnosis for the AIDS group, and 21.5 years after diagnosis for the non-AIDS group.
Discussion: Our results support the expansion of HIV screening programs to minimize delay in diagnosis. With continuing advances in HAART, this estimate of survival in initially asymptomatic patients may be conservative. Their long life expectancy raises questions about what kind of preventive heath services should be offered. These should be addressed through further analysis of overall benefit and cost-effectiveness.