Incentivizing HIV prevention

Our podcast interviews professor Omar Galarraga, who explains that everything from cash to coupons, to a simple redesign of a form, can make HIV treatment and prevention more accessible.

In the past few years, the field of public health has become more visible than ever before, but it's always played a crucial role in our daily lives. Each month, the Humans in Public Health podcast introduces a person who makes this work possible. Today, Professor Omar Galarraga.

We’ve come a long way when it comes to treating HIV. There are effective medications to slow down and prevent the spread of the virus. And in general, it’s easy to get tested. But despite all of these resources, about 1 in 4 people with HIV aren’t getting the care they need.

Professor Omar Galarraga says small incentives can help. His research shows that everything from cash to coupons, to a simple redesign of a form, can make HIV treatment and prevention more accessible. 

Listen to the Episode

Megan Hall  0:52  

Professor Omar Galarraga, thank you so much for joining me today.

Omar Galarraga  0:56

Thank you so much, Megan, for inviting me. It's a pleasure to be here.

Megan Hall 0:58

Most of your research looks at how to use incentives to encourage people to either get treated or tested for HIV. But it's part of a bigger field, which is called behavioral economics. Do you mind explaining just generally what that is?

Omar Galarraga  1:15  

Sure. Behavioral economics is basically the marriage of psychology and economics. It's a field that it's been around for over 50 years at this point. Research that was done in the early 70s, by two very famous people, Kahneman and Tversky. And basically, they demonstrated that we humans are not robots, right? That we cannot have in our brain, all the information that we need to make every decision and that we cannot do all the calculus that we would need to do to make, you know, the most rational, perfect decision. That we as humans make shortcuts, and that we rely on those on the shortcuts, to make many decisions. 

Megan Hall  1:55  

So it's kind of acknowledging that economics is describing people in a perfect environment with all the information but no one really makes decisions that way.

Omar Galarraga  2:04  

That's right. And that is very, very difficult for every decision to be perfect in the economic sense, To be quote, unquote, rational.

Megan Hall  2:12  

So how do we use behavioral economics to encourage someone to get tested for HIV or do something else that prevents the spread of the virus?

Omar Galarraga  2:22  

Right. So behavioral economics interventions have become very powerful because they use these deviations that we have from perfect behavior, in favor of prevention and treatment. So one very good example is opt-out. Right? So for whatever reason, many of us may be reluctant to take an HIV test: because of stigma, or because of fear of needles or for many other reasons. Yet, of course, it's you know, it's just a small prick in the finger and it passes very quickly. There's nothing to be afraid of, and it's very good knowledge to have for oneself and for one's sexual partners. And so opt-out has been very good, meaning that people will say, you know, we will do an HIV test on you, unless you actively opt out.

Narration 3:12

Omar says that testing patients for HIV by default when they go to the doctor has dramatically increased the percentage of people who get tested. In Botswana, this simple change helped  it become one of the first countries to reach the UN’s 95, 95, 95 targets on AIDs prevention. 

Narration 3:30

Those 95s represent percentages…. So- 95% of the people who have HIV have been tested for the virus. Out of those, 95% are receiving treatment. And in 95% of the people receiving treatment- virus is so low in their system that they're not transmitting the virus on to sex partners.

Megan Hall  3:49 

And you think something as simple as opting out instead of opting in to an HIV test made that possible?

Omar Galarraga  3:55  

Right. That's the amazing thing with some of these interventions, it seems so simple, and they're, you know, low cost or zero cost. But again, it's just that we humans are, as I said, not perfect, and the way that you pose, in this case, the test and the way you ask, it's very, very important. 

Megan Hall  4:13  

That's interesting, because when I heard of behavioral economics, my first thought was, we're paying people money, but you're saying, it doesn't necessarily mean that you're incentivizing people with cash or coupons, it could be just improving the user experience.

Omar Galarraga 4:29

That's right. That's right, that the most powerful applications are either no incentives at all, or very small incentives. A lot of the most recent applications in HIV are these applications where they're called nudges, right? And a nudge is obviously something that usually does not involve a financial incentive, but that involves a change in what is called the “choice architecture.” So that's the environment in which you know, a person makes decisions about HIV prevention and treatment. And really small changes can have big impacts.

Narration: 5:03

But sometimes those small changes do involve money or vouchers to encourage behavior. Omar was working in Mexico in 2006 when he first saw one of these programs in action. 

Omar Galarraga 5:15

I had heard about the Progresa Oportunidades program.  It’s perhaps the most famous– the first big Conditional Cash Transfer Program, which was, you know, paying families to keep school aged children in school and paying families to take their children to checkups and welfare visits. 

Narration: 5:32

The program was really successful. It increased education levels, improved health outcomes for children and helped reduce rural poverty in Mexico. Omar was impressed, so he decided to try something similar to  encourage HIV prevention. 

Omar Galarraga 5:46

Mexico had done it for the population at large, but nobody had done it with particular groups that were at high risk of acquiring HIV. So we interviewed over 1600 men who have sex with men. We went to the gay bars.  And then interviewed people while they were, you know, waiting to come in. Young people sometimes, you know they were there before the doors were open. And so they were like “sure I'll take 20 minute survey,” and they told us about, you know, how they would be interested– “Yeah, sure. I’ll come to the clinic every three months.” Or “yeah, sure, come to the clinic every month to be tested.” 

Megan Hall 6:20

If I get $15?

Omar Galarraga 6:22

Right, exactly. “If I get you know, five bucks? 10 bucks? 15 bucks? 20 bucks?”

And with that, we determined, you know, the optimal incentive.

Megan Hall  6:30

So for the original research, they had to come to the clinic and get a STI test. And if they were clean, they got the incentive?

Omar Galarraga 6:38

That's right. That's right. 

Megan Hall  6:40 

So it incentivized them to be having safe sex?

Omar Galarraga 6:43


However, and this is part of how I got interested in this, one of the first things that that we documented when working with the groups at highest risk, which are the men who are engaged in commercial sex work, is that there is a risk premium. Meaning that condomless sex is paid about 30% higher, right? So there's about a 30% premium on condomless sex. So if from the public health point of view, we said, well, you have to reduce the number of partners or you have to use condoms 100% of the time, that has an economic implication for the sex worker.

Megan Hall  7:17 

And that's behavioral economics too right?

Omar Galarraga  7:18  

Right. And that's why we felt like they need to be compensated to reduce the risk, because they're reducing the risk for themselves, but they're, they're also reducing the risk for society as a whole.

Narration: 7:29

Omar’s interventions have evolved over time, in part to keep up with new treatment options. 

Omar Galarraga 7:34

In Mexico, for example, we just finished a program with incentives for men at very, very high risk of HIV: men who are engaged in commercial sex work. And we basically pay them between $10 and $15 every three months for them to adhere to the PrEP, which is a pill that you take every day to avoid getting HIV infection. And, you know, we have preliminary results to suggest that adherence increased.  

Megan Hall 8:02

And how do you have the participants prove that they were taking PrEP to get their financial incentive? Because you're not watching them every day? Right?

Omar Galarraga 8:11

That's right, that's right. In this case, if I take an antiretroviral every day, the antiretroviral starts accumulating in my hair. So from the participants, we take about 150 strands of hair, and that gets analyzed. And then we can tell whether they've been taking, you know, five, six or seven pills spent the last week, three or four pills in the last week, or two or fewer pills in the last week.

Megan Hall  8:34 

What about long term behavior change? ? I mean, it's one thing to have an intervention that's a year long that pays people to come in every few months, it's another thing to make sure that they're taking PrEP for the rest of their lives.

Omar Galarraga  8:49 

Right, so the idea here is to, to start with incentives, but we coupled them with other cues. So there is research, for example, that if I start taking a pill every day, but that I initially may get paid for it– a little money. Again, we're not talking, you know, undue influence, right? We're just talking small nudge, again you know, $1. And so if I couple the behavior of taking it with something else that I'm doing like with, I don't know, brushing teeth, or setting the alarm clock or something else, then that cue gets reinforced. And eventually, you may be able to remove the incentive, and just the cue, the brushing of the teeth, or the setting the alarm or any other cue that you've put in place, and then the short term behavior can become a longer term right? If all you need is a small nudge, because, you know, you already have the intrinsic motivation. 

Megan Hall  9:44

So it's sort of like you're providing rewards or nudges in the beginning to get them to establish a habit. And then once the habit is formed, you can kind of remove those rewards? 

Omar Galarraga  9:53  

That’s right. And that's why some colleagues call this habituation. There is however, one thing that we have to take into account, you know, why is it that I'm not taking the pill? 

Narration: 10:05

Omar says that there is a limit to what behavioral economics can do. Sometimes it’s not possible to maintain the habit once the temporary payments end, especially when structural forces like poverty stand in your way. Take, for example, getting to the clinic to pick up pills. 

Omar Galarraga 10:21

If I don't get that incentive to be able to afford the bus ticket, then this is not going to make me any good even though I have the internal motivation to take the pill. And so we have to be careful with that, because … sometimes I feel like we ask these economic-based interventions too much. I think it depends on why is it? You know, what's the bottleneck? Why is it that I'm not taking the pill every day? And we have to be careful on that.

Narration: 10:44

But Omar says there’s still a lot that behavioral economics CAN do. He and his colleagues are pushing more countries to use those strategies, especially when it comes to HIV prevention.

Omar Galarraga 10:55 

I think having larger programs at the national level that are well thought out, and that rigorously evaluated, it's our goal. And that, you know, the small pilots that we’ve worked on, how can we bring them to scale? And how can we do them at a national level so that more people can have healthier and productive lives.

Narration: 11:17

Omar says we already know these programs are effective and relatively inexpensive. Now all that’s left is putting them to use.

Outro Narration: 11:26

Omar Galarraga is an Associate Professor of Health Services Policy and Practice at the Brown University School of Public Health

Humans in Public Health is a monthly podcast brought to you by Brown University School of Public Health. This episode was produced by Nat Hardy and recorded at the Podcast studio at CIC Providence.

I'm Megan Hall. Talk to you next month.