(Vancouver) – HIV patients starting treatment are nearly three times less likely to die than those who began in the mid-90s, says a large study authored by the B.C. Centre for Excellence in HIV/AIDS.
The study, published in the current issue of AIDS, examines how the evolution of antiretroviral therapies over the past 12 years have impacted HIV patients’ life expectancy in B.C. The study represents one of the largest comparative evaluations yet published.
Results show that patients who started therapy in 2002-2004 were nearly three times less likely to die than those who started in 1993-1995.
The study reveals health outcomes have steadily improved since the adoption of triple-drug therapy (formally known as highly active antiretroviral therapy, or HAART) in the mid-90s as the standard for treatment. The number of participants starting on three or more antiretroviral drugs was highest during 2002-2004.
However, other clinical advances are also attributable to the improvement in clinical outcomes, says Dr. Julio Montaner, Director of the B.C. Centre for Excellence in HIV/AIDS and one of study authors.
“Decreased mortality and increased life expectancy rates are attributable to the development of triple-drug therapy regimens and their superior efficacy to earlier regimens,” says Montaner.”As well, we now have more information to work with thanks to resistance testing, highly accurate viral-load detection assays and advances in genetic research.”
The Centre study reveals life expectancy at age 20 increased by 14.5 years for those who initiated therapy with CD4 counts below 200 microlitres (µL) – from 9.1 years in 1993-1995 to 23.6 years in 2002-2004. CD4 cells are white blood cells responsible for coordinating much of the immune response and are one of the main targets damaged by HIV. Most people have a CD4 cell count of 400 to 1,400 cells/ µL (an HIV-infected patient at risk of rapid disease progression is under 200 cells/ µL).
Improved health outcomes have also coincided with increased therapy options over the 12-year period. In 1993-1995, patients were provided eight drug regimen options – a stark contrast to the possible 53 different drug combination regimens available in 2002-2004. As well, current regimens offer improved safety and tolerability profiles, along with decreased pill burden and ease of administration.
The study also highlights the dramatic difference in potential years of life lost within the time periods. From 1993-1995, there were potentially 6,005 years lost per 1,000 population on therapy; for 2002-2004,1,233.
Treatment regimens were categorized into three different classes based on the number of drugs taken: mono, dual or therapies containing three of more antiretroviral drugs (i.e. triple-drug therapy).