Estimation of survival of HIV AIDS patients on antiretroviral therapy and predictive performance of survival models for censored data

Abstract

The first case of AIDS was detected in United States in early eighties is a disease caused newlineby human immunodeficiency virus (HIV). The initial stage symptoms may comprise newlinefever, sore throat, skin rash, lymphadenopathy, splenomegaly, myalgia, arthritis, and newlinemeningitis that occur with varying degree of severity. Later on, low level of viral newlinereplication and a steady fall in CD4 count may starts where the patient can remain newlineasymptomatic for several months to years termed as clinical latent period. The average newlineprogression time from HIV infection to AIDS is quite large. Patients with lower CD4 newlinecounts (lt 200 cells/and#956;l) are more at risk for developing opportunistic infections (OIs) like newlinetuberculosis, toxoplasmosis, cryptococcal meningitis etc. The mortality among the newlinepatients with CD4 lt 200 is around 19 times higher than those with CD4 counts gt 350. newlineThe common clinical features of disease progression could be chronic fever, persistent newlinecough for more than a month, chronic diarrhea, oral candidiasis, severe chronic herpes newlinesimplex virus (HSV) infection, more than10% loss of body-weight within a month, and newlineincidence of tuberculosis. The HIV transmission may be occurred either direct contact of newlinea mucous membrane or the infected blood contacts such as sexual intercourse newline(vaginal/anal/oral), infected blood, semen, vaginal fluid, preand#8208;seminal fluid contaminated newlinehypodermic needles between mother and baby during pregnancy or child birth or breast newlinefeeding. newline newlineThe extent and severity of HIV/AIDS can be recognised as the start of the epidemic, newlinearound 78 million (71 87 million) people have become infected with HIV, and 39 million newline(35 43 million) people have died of AIDS-related illnesses. Approximately 35 million newlinepeople (33.2 37.2 million) were living with HIV worldwide in 2013, a 17% increase newlinefrom 2001. Africa being on the top with nearly one HIV infected in every twenty adults newline(15+ years) accounting alone 69% problem globally followed by the Caribbean, Eastern newlineEurope and Central Asia with 1.0% affected living adults...