Risk factors and causes of death in the Australian HIV Observational Database

Mortality rates in HIV-infected people remain high in the era of highly active antiretroviral treatment (HAART). The objective of this paper was to examine causes of deaths in the Australian HIV Observational Database (AHOD) and compare risk factors for HIV-related and HIV-unrelated deaths.

Data from AHOD, an observational study of people with HIV attending medical sites between 1999 and 2004, were analysed. Primary and underlying causes of death were ascertained by sites completing a standardised cause of death form. Causes of death were then coded as HIV-related or HIV-unrelated. Risk factors for HIV-related and unrelated deaths were assessed using survival analysis among patients who had a baseline and at least one follow-up CD4 and RNA measure.

The AHOD had enrolled 2329 patients between 1999 and 2004. During this time, a total of 105 patients died, with a crude mortality rate of 1.58 per 100 person years. Forty-two (40%) deaths were HIV-related (directly attributable to an AIDS event), 55 (52%) HIV-unrelated (all other causes), and eight had unknown cause of death. Independent risk factors for HIV-related deaths were low CD4 count and receipt of a larger number of antiretroviral treatment combinations. Among HIV-unrelated deaths, low CD4 count and older age were independent risk factors.

In AHOD in the HAART era, mortality in people with HIV remains around 10-fold higher than in the general population. In our analyses, HIV-unrelated deaths were associated with more advanced HIV disease in a similar way to HIV-related deaths.