Study sheds light on HIV ART-naïve population

ART is underused, findings suggest

A national study has found that antiretroviral therapy (ART) drugs are underused among people who seek HIV care from HIV clinics at seven sites across the United States.

"A full third of people were not on ARTs even when in clinic care," says Julie Dombrowski, MD, MPH, deputy director for clinical services at the Public Health Seattle in King County (PHSKC) HIV/STD Control in Seattle, WA, and an acting instructor of infectious diseases at the University of Washington in Seattle.

Investigators found a population-based way to measure how many HIV patients are on antiretroviral drugs and how many are not. They examined data, between 2000 and 2008, from seven Centers For AIDS Research (CFAR) sites, including locations in Seattle, San Diego, CA; Cleveland, OH; Baltimore, MD; Boston, MA; Birmingham, AL, and Chapel Hill, NC.

"These are premier HIV centers and the largest providers of HIV care in their respective areas," she explains.

Half of the people who were not receiving drugs had clinical indications of needing them, she adds.

"We don't fully understand the reasons why those people are not on ART," Dombrowski says. "We know that mental health, substance use, and insurance issues are related, but we don't have a great sense of the distribution of those reasons."

"The factors associated with not being on antiretroviral therapy were younger age, not being in continuous HIV care, and injection drug use (IDU)," Dombrowski says.

Researchers determined which patients should have been on therapy according to the HIV treatment standards of the time period associated with the population. So as standards were revised, they accounted for those changes in their study.

"The cutoff for initiating therapy has changed over time," Dombrowski says. "In 2008, for instance, among that third of people not on therapy half had CD4 counts under 350 cells, which was a clear indication for therapy at that time."

Also, 77% of the patients in 2008 had CD4 counts below 500, she adds.

"In populations with CD4 counts above 500 the best approach is not agreed upon, so we have a clinical conundrum," she says.

While some HIV experts argue that it's better to start ART as soon as feasible because of the public health benefit of reducing HIV transmission, this might not be as compelling an argument to clinicians, Dombrowski notes.

"We have to take into consideration the benefits to the individual first and foremost," she says.

The study also found some geographical variation in the findings.

For example, in the Baltimore population there was a higher proportion of people in therapy with lower CD4 counts, indicating late diagnoses, Dombrowski says.

"There was a lower proportion of patients on therapy and a higher proportion of people not on therapy," she adds. "They have a higher proportion of injection drug users in Baltimore, and that's one factor associated with not being on ART."

Researchers are going to continue to evaluate the findings and try to determine the reasons why patients were not placed on ART.

"We're working on that now and also are designing interventions to increase ART use," Dombrowski says. "The message to focus on is that a third of our patients, even those engaged in care, are not taking antiretrovirals and most of them have clinical reasons why they should be taking it."

So HIV clinicians should look at their own patient populations, find out who is not on ART and address that problem.

"Sometimes they might need to have a conversation with patients about their lives, connect patients to ancillary services, and re-evaluate the barriers to ART use," Dombrowski says.