SLIDE-OPERANT CONDITIONING TO PROMOTE ART ADHERENCE
We are in the process of conducting a study to evaluate a novel incentive intervention to promote
adherence to antiretroviral medications for people living with HIV.
SLIDE Antiretroviral Therapy for HIV
Daily use of antiretroviral medications can reduce the amount of HIV in the blood, which is called viral
load, to undetectable levels. If people take antiretroviral medications regularly, that can increase undetectable
viral loads and thereby improve health, increase lifespan, and reduce the risk of transmitting HIV infection to
others. And the Joint United Nations Programme on HIV/AIDS suggests that we can eliminate the HIV/AIDS
epidemic if 73% of people living with HIV take antiretroviral medications regularly and achieve undetectable
viral loads, a level well above that observed in Baltimore and many other areas.
SLIDE Incentives to Promote ART Adherence
Despite the benefits of antiretroviral therapy or ART, many people living with HIV do not take the
antiretroviral medications regularly. Financial incentives have been use to promote adherence to antiretroviral
medications by giving participants incentives for opening the pill bottles or by giving participants incentives for
providing bloods samples with decreased or undetectable viral loads.
SLIDE Multi-Site Studies of Incentives for Viral Suppression
Here are the results of the two most important studies. These were both large multisite studies. One
study by the HIV Prevention Trials Network included over 16,000 participants, but in that study financial
incentives only increased the percentage of people with undetectable viral loads by 3.8%. The other study,
which was conducted by NIDA’s Clinical Trials Network, included 801 participants, found that incentives did
not affect the percentages of participants with undetectable viral loads.
SLIDE Incentive Interventions in Multisite Studies
These multisite studies seemed to show that financial incentives had little or no effect on viral load in
people living with HIV. However, these studies used low magnitude and delays incentives. In both studies,
participants could earn less than $1 per day for providing blood samples with undetectable viral load after
between 3 and 6 months.
SLIDE Experimental Design
We conducted a study to evaluate an incentive intervention for suppression of viral load that had a
strong empirical foundation. This slide displays the experimental design of the study. Participants with
detectable viral loads completed an HIV education course and were then randomly assigned to a Usual Care
Control group or an Incentive group. The Incentive intervention lasted for 2 years. Participants in both groups
were assessed every 3 months for two years.
SLIDE Incentive Intervention
This slide shows some of the main features of the incentive intervention: Participants earned incentives for
having a decreased or undetectable viral load. We used a high incentive magnitude in which participants could
earn $10 per day for meeting the viral load criterion. Because it could take several weeks to reach an
undetectable viral load, initially participants could earn an incentive if their viral load decreased at a rate of
about 30% per week. And the incentive intervention was in effect for two years, participants could earn up to
$7,300 for maintaining a decreased or undetectable viral load over that two-year period.
SLIDE Demographic Characteristics
Most participant in this study were unemployed and lived in poverty.
SLIDE Undetectable Viral Loads During First Year
This slide shows the percentage of participants that had undetectable viral loads at Intake to the study
and at the 3-, 6-, 9-, and 12 assessments after random assignment. No participants had an undetectable viral
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Silverman—ABA Addictions Conference 2018
load at intake, but significantly more Incentive participants had undetectable viral loads at the 3-, 6-, 9-, and 12month assessments than Usual Care Control participants.
SLIDE Undetectable Viral Loads During First Year (2)
This figure shows the percentage of blood samples provided by participants in the two groups during the
first year after random assignment that had undetectable viral loads. The dots represent individual participants
and the bars represent group means. As you can see, over 70% of the bloods samples provided by incentive
participants had undetectable viral loads compared to less than 30% for Usual Care Control participants, which
was statistically significant and represented an increase of over 30%.
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