A study conducted by researchers from the University of Bristol analyzed survival rate trends among HIV-positive patients from the United States and Europe.
The landscape changed dramatically for HIV-positive people in 1996, the first year in which antiretroviral therapy (ART) was available. After patients began recieving ART, HIV went from a death sentence to a condition that could be managed with proper care. However, the gains in longevity have not been evenly distributed across the two decades since ART became commonplace. A team of researchers at the University of Bristol in England decided to examine the trends in life expectancy through 4 distinct calendar periods—1996 to 1999, 2000 to 2003, 2004 to 2007, and 2008 to 2010.
Incorporating data from 18 different cohorts in the United States and Europe, the study included data on 88,504 HIV-positive patients aged 16 or older, who began a regimen of ART anywhere between 1996 and 2010. The researchers tracked how many patients died in the first 3 years of taking ART, along with patients’ CD4 cell counts, viral loads, age, sex, and if they had a history of injecting illegal drugs.
The percentage of deaths within 3 years of starting ART decreased over time—6% of the subjects died in the 1996 to 1999 and 2000 to 2003 cohorts, 4% died in the 2004 to 2007 cohort, and 3% died in the 2008 to 2010 cohort. The decline in death rate was consistent across continents, age groups, and baseline CD4 cell count. One reason for this may be the move to more effective, less toxic ART regimens. In the earlier years of ART, most patients were put on a protease inhibitor-based regimen, which carried specific risks. After 2000, non-nucleoside reverse transcriptase inhibitors, which carry less risk, have been the standard of care. The most recent regimens have been streamlined to 1 pill once a day, in many cases, likely increasing adherence.
One notable exception to the consistent decline in post-ART mortality has been the population of HIV-positive people with a history of drug injection. According to the scientists, injecting drugs, even if someone is on ART, is correlated with poorer outcomes. These subjects have seen a decline in mortality, but it has not been as precipitous as the decline in mortality seen in the non-drug-injecting participants.
“We do not know if those who were infected via injection-drug use continue to inject drugs,” Margaret May, professor of medical statistics at the University of Bristol and an author of the study, told Contagion®. “We use transmission risk as a proxy which marks out people to be at higher risk of death. The higher risk may be due to many reasons. Some of these could be due to ongoing drug use (more likely to die of overdose or mental health problems, less likely to adhere to ART drugs) and some due to historic drug use (for example, coinfection with hepatitis C leading to liver problems). It is also a marker of social marginalization (homeless, less likely to be employed, etc.), all of which can lead to worse health.”
Overall, the researchers say, there has been a remarkable improvement in the survival rate of HIV-infected individuals, between 1996 and 2013 (the latter being the year in which people who began taking ART in 2010 were measured). The decline in mortality was particularly notable in the 2008 to 2010 cohort. In the two decades that ART has been available, HIV patients have seen their life expectancy rise by about 10 years, and those who began ART as recently as the 2008 to 2010 time period now have an estimated life expectancy almost as high as that of uninfected people.
“The key to preserving life expectancy is to get diagnosed early in the course of infection and start treatment early, before their immune system is damaged,” Dr. May told Contagion. “It is now recommended by WHO that everyone diagnosed with HIV should be offered immediate treatment with ART. This also has the public-health benefit of preventing transmission of HIV because ART should stop the virus replicating, and so people successfully treated are unlikely to be infectious.” Other recommendations for increased longevity include quitting smoking, stopping drug use, and treating any comorbidities, such as hepatitis.
Laurie Saloman, MS, is a health writer with more than 20 years of experience working for both consumer and physician-focused publications. She is a graduate of Brandeis University and the Medill School of Journalism at Northwestern University. She lives in New Jersey with her family.