In industrialized countries, HIV positive individuals who acquired the disease sexually experience rates of mortality similar to the general population in the first five years following infection, though the risk of death continues as the duration of the infection becomes longer than this period. These results were published in an article released on July 1, 2008 in JAMA.
Since a highly active antiretroviral therapy (HAART) was introduced in many industrialized countries, several studies have shown great decreases in mortality rates of persons infected with the human immunodeficiency virus (HIV). The authors of the study point out that monitoring these mortality levels are important to evaluate the best policy in tackling this disease. “It is important to provide up-to-date and robust estimates of expected mortality as anti-HIV drugs and strategies continue to improve. Such estimates help policy makers and those planning health care to monitor the effectiveness of treatments at a population level and provide an indicator of the ongoing and likely future impact of HIV disease on health care needs.”
To examine the effectiveness of HAART on levels of HIV mortality, Krishnan Bhaskaran, M.Sc., of the Medical Research Council Clinical Trials Unit, London, and colleagues assessed the changes in excess mortality of HIV-infected individuals in comparison with the uninfected population. HIV seroconversion, a name for the process in which the body develops antibodies in response to the infection, was monitored in conjunction with mortality, and in a multinational collaboration, called CASCADE, was compared with expected mortality in the general population. Based on these factors, a model was created with adjustments for infection duration in order to analyze the changes in excess mortality over calendar time in HIV infected subjects. The data was collected in 2007, encompassing those at risk between the years 1981 and 2006.
A total 16, 534 subjects were analyzed and the population had a median follow-up duration of 6.3 years. By December 2006, a total 2,571 individuals had died — while a general population cohort would have been expected to lose 235. Before 1996, the excess mortality of HIV positive patients per 1,000 person-years, was 40.8, but this number decreased in each following calendar period, culminating in an excess mortality of 6.1 per 1,000 person years in the period 2004 to 2006. By this period, no evidence was found of excess mortality within 5 years of seroconversion, but, in the longer term, some additional mortality was found, with a higher excess probability of death in the first 10 years from seroconversion.
The authors write that this trend is significant for the treatment of HIV positive individuals: “Considering the first years following the widespread introduction of HAART, we have estimated an 88 percent reduction in excess mortality in 2000-2001 compared with pre-1996, corresponding closely to the 87 percent reduction in the standardized mortality ratio in 1997-2001 compared with pre-1996, as reported by the Swiss HIV cohort. Our more recent data show that reductions have continued to 2004-2006, with excess mortality in this period 94 percent lower than pre-1996 levels. Corresponding to these reductions, the uptake of HAART increased, and though this leveled off after 2001, there followed an increasing use of nonnucleoside reverse transcriptase inhibitor-based HAART as the first-line treatment regimen and a substantial increase in the boosting of protease inhibitor-based regimens.”
A higher risk of excess mortality was associated with a few factors, including: older age at seroconversion, comparing particularly 45 years or older to the 15-24 year age range; and higher exposure to injection drug use, in comparison to sex between two males. Overall, females were at lower risk than males.
In conclusion, the authors indicate that this represents a significant improvement in care for patients with HIV: “Our results show the progress in reducing mortality among HIV-infected individuals toward the levels experienced by the general uninfected population. However, there is continuing excess mortality, particularly evident in those infected for 10 years or more. Ongoing monitoring of excess mortality will be important as new treatment advances are implemented in an attempt to further reduce mortality rates among HIV-infected individuals.”
Changes in the Risk of Death After HIV Seroconversion Compared With Mortality in the General Population
Krishnan Bhaskaran; Osamah Hamouda; Mette Sannes; Faroudy Boufassa; Anne M. Johnson; Paul C. Lambert; Kholoud Porter; for the CASCADE Collaboration
JAMA. 2008;300(1):51-59.
Written by Anna Sophia McKenney