All-cause Mortality in Treated HIV-infected Adults with CD4 ≥500/mm3 Compared with the General Population: Evidence from a Large European Observational Cohort Collaboration

Background: Using data from a large European collaborative study, we aimed to identify the circumstances in which treated HIV-infected individuals will experience similar mortality rates to those of the general population.

Methods: Adults were eligible if they initiated combination anti-retroviral treatment (cART) between 1998 and 2008 and had one prior CD4 measurement within 6 months. Standardized mortality ratios (SMRs) and excess mortality rates compared with the general population were estimated using Poisson regression. Periods of follow-up were classified according to the current CD4 count.

Results: Of the 80 642 individuals, 70% were men, 16% were injecting drug users (IDUs), the median age was 37 years, median CD4 count 225/mm(3) at cART initiation and median follow-up was 3.5 years. The overall mortality rate was 1.2/100 person-years (PY) (men: 1.3, women: 0.9), 4.2 times as high as that in the general population (SMR for men: 3.8, for women: 7.4). Among 35 316 individuals with a CD4 count ≥500/mm(3), the mortality rate was 0.37/100 PY (SMR 1.5); mortality rates were similar to those of the general population in non-IDU men [SMR 0.9, 95% confidence interval (95% CI) 0.7-1.3] and, after 3 years, in women (SMR 1.1, 95% CI 0.7-1.7). Mortality rates in IDUs remained elevated, though a trend to decrease with longer durations with high CD4 count was seen. A prior AIDS diagnosis was associated with higher mortality.

Conclusions: Mortality patterns in most non-IDU HIV-infected individuals with high CD4 counts on cART are similar to those in the general population. The persistent role of a prior AIDS diagnosis underlines the importance of early diagnosis of HIV infection.