Q: How effective is Exposure Notification in the United States?
Health Equity & Exposure Notification Technology
Digital, privacy-preserving contact tracing apps using BlueTooth exposure notification (EN) technology have proven to be effective, especially in the United Kingdom, where the app is estimated to have reduced the size of the second wave by a quarter. But the implementation of EN technology has raised legitimate questions about health equity. Suppressing the spread benefits everyone, but is that good enough if EN technology disproportionately benefits smartphone users and therefore exacerbates health inequities? Would EN implementation be worth it if it reduced the absolute prevalence of disease in disadvantaged populations, even if the reduction among the privileged were larger? Or would an investment in EN technology end up redirecting resources that could be better invested more equitably?
First, let’s consider the facts rather than the fears about the digital divide. Smartphone ownership doesn’t vary much by race/ethnicity: in early 2021, rates for American adults were 85%, 85%, and 83% for whites, Hispanics, and African Americans, respectively. Indeed, in a survey conducted about the Covid Watch app in Arizona1, Hispanics (64%), American Indians (66%), African Americans (66%) and Asians (72%) all thought that the app was a great or good idea, at higher rates than Whites (62%). It is clear that there is both appetite and ability to leverage this technology across many different cultures and ethnicities.
Income is more predictive of smartphone ownership, but even so, 76% of Americans making less than $30,000 yearly own a smartphone. That’s not so bad, although more data is still needed on low-energy Bluetooth performance for older and cheaper Android models. Smartphones are in some ways a more important technology for low-income Americans, many of whom depend heavily on their smartphones for information access; what they tend to lack is broadband internet or a home computer. If uptake of an EN app could be achieved by low-income populations, and is well-designed for ease of use, it could help direct them to local, free resources for testing, vaccines, or other assistance. This would help reduce inequities in access to quality information—for example, less than 30% of the high medical risk COVID-19 patients eligible for monoclonal antibody treatment are getting it. It’s important to realize that for EN technology to work, intermittent internet access is enough, e.g. from free public wi-fi hot spots used by someone who cannot keep up with monthly payments on a data plan. We have made great progress on the digital divide on the smartphone front—it is other areas, like broadband access, where the digital divide is worst.
It is the elderly, rather than those experiencing poverty, who are the least likely to use smartphones, with only 61% of Americans over the age of 65 having one. But here it is important to address a misconception head on. EN apps do NOT protect their users from disease, so we cannot conclude from the fact that the elderly lack smartphones that the elderly benefit least from the technology. This is because an EN app does nothing to stop its user from getting infected, but instead protects the user’s contacts, and the user’s contacts’ contacts—even when the people who are protected do not use the app themselves. When an exposure notification stops an asymptomatically infected son from visiting his elderly mother, it is the mother, not the son, who benefits most. The elderly are best protected not when they use the app, but when their younger family members, caretakers, and those they come into contact with at grocery stores, restaurants or elsewhere, all use the app.
This lack of benefit to the app’s users is of course also the weak spot of the technology (and not just on equity grounds). Even more than other measures like masks and vaccination, using an EN app is an altruistic act that helps other people far more than it helps you. This brings up an entirely different equity concern, a concern that also applies to manual contact tracing. The purpose of the app is to tell you when you are exposed, and when that happens, the app might ask you to quarantine. Quarantine has a disproportionate impact on vulnerable populations, especially in places like the US where there is no monetary assistance, let alone full wraparound services and support. Even if we decide in the interests of equity, and at this later stage of the pandemic, to drop the quarantine recommendation in favor of daily rapid testing, an asymptomatic individual who tests positive will still be asked to isolate, and may lose income in the service of protecting others.
How do we get EN apps, or any other test and trace policies, to help those who need help most? Luckily, the development of monoclonal antibody treatments, effective only if given early, has fundamentally changed the game on this. Already, our app has been prompting users to self-assess, after receiving a positive test result and entering their verification code, whether they are at high risk of severe outcomes, and to ask their doctor about early treatment if they are. More radically, the FDA recently also approved therapy for post-exposure prophylaxis. This means that if a person is exposed to someone with COVID-19, instead of just watching and waiting and testing and quarantining, individuals at high risk can now receive treatment so early that it can stop them getting infected altogether. For the first time in this pandemic, getting contact traced can help the individual, not just others. This can make contact tracing in disadvantaged communities a win for equity, not a liability. WeHealth is committed to helping disadvantaged communities, especially Tribal Nations.
There is a broader question in how best to fight inequities. Does fear of exacerbating inequality hold you back from doing things you would otherwise do, or does the desire to serve those who need it most push you to do all that and more? In public health response to the pandemic, our answer needs to be “yes, and…” Yes to vaccines, yes to improving ventilation, yes to masks, yes to mass testing, yes to manual contact tracing—and yes to exposure notification tech too. And as we do all those things, we need to make extra effort to reach (through targeted marketing and community organizing) and support those who need it the most, e.g. offering wraparound services to those asked to isolate or quarantine, and treatment/prophylaxis. We will learn as we go, but first we need to try. To try not only to stop disease spread in all communities, but also to try to reduce the burden of quarantine on those who can least afford it, and offer treatment and support to those who need it most.1Noriko Tamara, Paloma Beamer, Sudha Ram, Yuanxia Li, Kacey Ernst. Statewide survey on exposure notification opportunities and barriers in Arizona. Report submitted to ADHS. December 2020.