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Ideas | Tyler Wray

Scientists have a new weapon against HIV: your phone

adobe/globe staff

In a fast-evolving fight against HIV, public-health workers have a powerful new ally: Most Americans at risk of contracting the virus carry powerful smartphones that they check again and again over the course of the day.

In recent years, we’ve seen revolutionary advances in HIV prevention that could help us achieve a sustained decline in new infections and envision an end of the epidemic. Smartphones can help us make the most of those advances.

By the mid-1990s, major breakthroughs in HIV treatment had upended the disease’s image as a “death sentence” and made it possible for those affected to lead long and healthy lives. Yet the number of new cases in many parts of the world has increased or remained stubbornly flat for much of the last three decades. For much of that time, condoms were virtually the only option to stop the spread of HIV through sex, and getting tested required an afternoon at the doctor’s office.


Since then, researchers have developed rapid, inexpensive self-testing options and discovered that some drugs used to treat HIV can also help prevent uninfected people from contracting it, an approach known as “pre-exposure prophylaxis” or PrEP. Studies also showed that treating new cases as soon as possible can prevent people from transmitting the virus, a strategy called “treatment as prevention.”

With more ways to prevent the spread of HIV than ever before, we’ve learned that using many options together works much better than any one strategy alone. Called “combination prevention,” this approach involves offering patients multiple medical and behavioral strategies for reducing their risk based on what is the best fit for them. Yet the success of combination prevention requires matching each person with the right interventions at the right time. It can also require a lot of from patients: periodic HIV testing, steady adherence to medication schedules, and good communication with medical providers.

Smartphones and other Internet-connected devices may hold the key. In 2017, more than three-quarters of American adults owned a smartphone, and that number continues to grow. People use their devices almost continuously, with studies suggesting that our phones are within arm’s reach 90 percent of the time and that we check them more than 2,600 times a day. The widespread adoption of smartphones, along with specialized devices, apps, and sensors, allows us to provide “just-in-time, adaptive interventions” that intervene at critical moments when someone is about to slip up and do something harmful or when they are most receptive to making a positive change.


Successful interventions depend on being able to continually monitor and communicate with users, which has only become widely possible with the advent of smartphones and other personal devices. When your Fitbit buzzes with a reminder to move because you haven’t completed your target number of steps for the hour, that’s a powerful, customized nudge you couldn’t receive without a device — unless you hired a personal trainer to follow you around all day.

The ever-increasing ubiquity and power of these devices provides an unprecedented opportunity to track and interact with patients to encourage healthier choices. Researchers and developers in this area, often called “mobile health” or mHealth, have created apps and devices to help people monitor and modify their exercise and eating habits, quit drinking or smoking, and manage their depression and anxiety.

Mobile health is beginning to transform HIV prevention and care as well, for example, by helping to connect people to self-testing and PrEP. Smartphones are ideally suited for reaching high-risk groups like young, single gay and bisexual men, many of whom frequent dating apps like Grindr, Jack’d, and Scruff. While these apps have often been criticized for facilitating hookups that may expose users to HIV, they could also provide potent opportunities to reach these men and encourage safer choices.


For example, Grindr recently began offering users the option to receive regular testing reminders and information about their nearest testing sites. The app’s ability to instantly share targeted information with millions of daily users far outpaces the reach of even the most prolific public health campaign a decade ago.

Just-in-time mobile health tools can serve as a key piece of the combination prevention strategy by complementing existing approaches and helping reach individuals with the right interventions at the right time. Consider self-administered, home-based HIV tests, which have revolutionized testing by allowing people to learn their status in the privacy and security of their own home. While they offer a powerful way to increase testing rates, they have one major drawback over traditional clinic testing: Users are left to face a highly vulnerable moment alone.

To address this challenge, our team at Brown University’s School of Public Health developed eTest, a system that uses Internet-connected devices to provide users with the support they need after testing themselves. When a user opens the HIV self-test kit, a Bluetooth sensor sends a signal to an app on the user’s phone, prompting a trained counselor to call the user, typically within an hour, to discuss their test results and offer relevant prevention and treatment resources. As one user we interviewed described it, the system “brings in that support structure that’s already in the medical clinic into the home.”


Our latest study found that gay and bisexual men who were given eTest were more likely than those supplied with standard self-testing kits to receive counseling on how to reduce their HIV risk, get prevention supplies like condoms, and obtain referrals for PrEP. Given these promising results, we plan to roll out eTest in Providence, Los Angeles, and Jackson, Miss., later this year, in partnership with local health agencies and nonprofits.

Our team at Brown is exploring other ways mHealth can deliver the right HIV interventions at the right time. For example, patients often naturally reflect on their level of risk when getting tested. We’re studying whether having people play interactive health games while waiting for test results could encourage them to commit to behavior changes that reduce their risk in the future. We’re also using Internet-connected pill bottles to monitor when patients are having trouble adhering to their HIV medications and instantly alert their doctors.

Some day soon, an approach known as “digital phenotyping” may even allow us to predict risky behaviors — like missing medication doses — in advance, using only data from patients’ normal day-to-day use of their smartphones. Our group is actively exploring whether applying the latest techniques in artificial intelligence to the rich data streams produced by people’s personal devices can help us discover these signals and deliver support before patients fall behind.


Of course, collecting data on sensitive health issues requires gaining people’s trust. Grindr recently came under fire for revealing users’ HIV statuses to two outside companies that were helping optimize its software. Developers of mHealth initiatives must be incredibly vigilant and thoughtful about privacy safeguards and how they store sensitive data.

HIV researchers continue to look for the next biomedical breakthrough for treating HIV. An equally critical task, though, is figuring out how to connect at-risk patients to the right set of existing interventions at the right time. In the years to come, smartphones and other devices will transform public health by allowing us to monitor people’s health continuously and intervene in the moments they need it most.

Tyler Wray is an assistant professor of behavioral and social sciences at the Brown University School of Public Health, where he researches ways technology can be used to improve HIV and STI prevention and care. He is the co-founder of SmashLabs, a nonprofit research group at Brown that develops and tests mobile health technologies.