Survival following HIV infection of a cohort followed up from seroconversion in the UK

Abstract

To estimate changes over calendar time in survival following HIV seroconversion in the era of HAART and to provide updated survival estimates. Using data from a UK cohort of persons with well estimated dates of HIV seroconversion, we analysed time from seroconversion to death from any cause using Cox models, adjusted for prognostic factors. Kaplan-Meier methods were then used to determine the expected survival in each calendar period. 2275 seroconverters were included with 18 695 person-years of follow up. A total of 444 (20%) died. The relative risk of death, compared with pre-1996, decreased over time to 0.63 [95% confidence interval (CI), 0.48-0.81], 0.24 (0.17-0.34), 0.14 (0.10-0.21), 0.08 (0.05-0.13) and 0.03 (0.02-0.06) in 1996-1997, 1998-1999, 2000-2001, 2002-2003 and 2004-2006, respectively. An elevated risk of death was associated with older age at seroconversion [hazard ratio (HR), 1.49; 95% CI, 1.34-1.66 per 10-year increase] and HIV infection through injecting drug use (HR, 1.53; 95% CI, 1.17-2.00). In 2000-2006, the proportion of individuals expected to survive 5, 10 and 15 years following seroconversion was 99%, 94% and 89%, respectively. Survival following HIV seroconversion has continued to improve over calendar time in our cohort, even in the more recent years of HAART availability. HIV seroconverters, by definition identified early in their infection, are likely to have the greatest opportunity for intervention; if similar high survival expectations are to be seen in the wider HIV-infected population, early diagnosis is likely to be crucial.