Abstract
HIV infection is characterized by a progressive destruction of the immune system, allowing for the occurrence of several, severe, opportunistic infections and diseases, leading to the clinical stage of AIDS. In Portugal, the national surveillance system for HIV/AIDS registered 17,825 pre-AIDS cases since January 1993 until 31 March 2008. The national database collects clinical, epidemiological and virological data, including dates of onset of major health events. The objective of this work is to study the time from diagnosis of HIV infection to the development of AIDS. Often, a patient may die prior to the development of AIDS, in a pre-symptomatic stage. This is a situation of competing risks because the individual may experience more than one event. The cumulative incidence function was used to estimate the probability of an event and a competing risks proportional hazards model was used to identify important prognostic factors. In this study, the main determinants towards disease progression to AIDS, as well as death prior to the occurrence of opportunistic infections, are the year of diagnosis, which reflects the availability of antiretroviral drugs (HAART), gender, age and transmission category.
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Acknowledgements
Cristina Rocha’s research is partially sponsored by national funds through the Fundação Nacional para a Ciência e Tecnologia, Portugal—FCT under the project PEst-OE/MAT/UI0006/2011.
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Alves, M., Rocha, C.S., Paixão, M.T. (2013). Survival Analysis Applied to the Study of Time from Diagnosis of HIV-1 Infection to AIDS in Portugal. In: Lita da Silva, J., Caeiro, F., Natário, I., Braumann, C. (eds) Advances in Regression, Survival Analysis, Extreme Values, Markov Processes and Other Statistical Applications. Studies in Theoretical and Applied Statistics(). Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-34904-1_4
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DOI: https://doi.org/10.1007/978-3-642-34904-1_4
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