In the spring of 2020, the first version of the covid-19 exposure notification system was released to the public. These systems promise to slow the spread of the disease by providing automatic warnings to those exposed to the virus.Now, more than a year later, more than 50 countries-Including half of the states in the United States-can choose to join these systems.
But the biggest question remains: how effective is this technology? Some research gives the answer, But despite such widespread introduction, it is difficult to assess whether exposure notices can really prevent the spread of covid-19. This is especially true in the United States, where many states have launched their own apps—a decentralized approach that reflects the decentralized pandemic response in the United States.
To learn more about the development of this technology in the United States, MIT Technology Review contacted every state public health department that activated a digital contact tracking system and checked app reviews left by anonymous Americans. We asked two questions: Who is actually using this technology, and how do people feel about it?
The final result of this analysis paints a picture of untapped potential. Many exposure notification applications in the country are underutilized, misunderstood and untrusted-but this technology may not yet become a public health tool for future disease outbreaks.
How the technology works
Contact notification was originally proposed as a supplement to traditional contact tracing. Under traditional manual methods, investigators looking for people who may have been infected require patients to track their whereabouts and activities through phone calls and interviews. This new technology is expected to automatically cover the entire population, not just small disease groups-this is a clear advantage for tracking rapidly spreading diseases.
For example, you may remember the friends you met at lunch, but not the strangers you stood by in line for 15 minutes at the grocery store. The exposure notification system will remember for you to anonymously use Bluetooth to record the logs of nearby mobile phones and alert you when one of the mobile phones is related to a positive test result.
The first wave of the system was designed by developers, most of which eventually worked with Apple and Google to create a unified standard. The Apple-Google system prioritizes user privacy, anonymizes their data, and does not track user location. With the support of the world’s two major telephone platforms, this system is the most widely adopted system and is used by most states in the United States.
It is well known that the effectiveness of these systems is difficult to assess.Research is just beginning to emerge U.K. application with Switzerland, E.g. In the United States, since each state is basically doing its own thing, evaluation becomes more difficult. But our analysis does have some key points:
- The U.S. system started relatively late in the pandemic-at that time most of the country’s autumn and winter peaks were already in progress
- The technology has not been widely adopted, although the situation in some states is better than others
- The public’s lack of trust in the new technology – coupled with the lack of resources of public health agencies peddling the technology – hinders adoption rates and the way people use the system
Who is using this technology
We tracked exposure notification apps launched in 25 states and the District of Columbia. Virginia was the first state to disclose the technology to its residents in August 2020, while other states are only just getting started.Massachusetts Started pilot testing of its application in two cities April 2021, and South Carolina is currently conducting a pilot project at Clemson University.The state actually started work on its system as early as May 2020 – but lawmakers Ban the public health department Due to privacy issues, any digital contact tracking work was carried out last summer, which hindered development.
Even in states that provide such applications, not everyone can use them.Contact notification only applies to smartphone users; and about 15% of Americans do not have a smartphone, According to the Pew Research Center. Nevertheless, more than half of the US population now has access to electricity. Whether they choose to join these systems is another matter.
Since most states do not report user data publicly, we directly contacted the state public health department and asked how many people chose this technology.
Twenty-four states and DC shared user estimates, indicating that as of early May, a total of 36.7 million Americans had chosen to receive notifications. Hawaii has the highest population coverage, about 46%. In four other states, more than 30% of residents chose to join: Connecticut, Maryland, Colorado, and Nevada. Seven other states have population coverage of more than 15%.
This ratio is very important: Modeling research It has been determined that if approximately 15% of the population chooses to join the system, the number of Covid cases, hospitalizations and deaths in the community can be significantly reduced. According to this indicator, 13 states (which together account for approximately one-third of the US population) received a certain degree of protection due to exposure notifications.
The remaining 11 states with exposure notification applications failed to meet this success benchmark. Of the 11 states, three have less than 5% population coverage: Arizona, North Dakota, and Wyoming. South Dakota is a state that has not responded to media requests, and it shares the use of the Care19 Diary app with the low activation states of North Dakota and Wyoming.
However, comparing states is not perfect because there are no federal standards to guide states on how to collect or report data—some states may make choices that are very different from others.For example, although the DC reported the “Exposure Notice Opt-in” number on it Reopen the indicator page, This number is actually higher than its residential population. A DC Health representative explained that the number of people who opted in includes tourists and people working in DC, even if they live elsewhere. For our purposes, we consider the activation rate of DC as part of the population of the surrounding metropolitan area (including parts of nearby Maryland, Virginia, and West Virginia).
Another reason these rates are difficult to measure: Several states with higher usage rates benefit from major upgrades Apple and Google released in September: Exposure notice Express, or ENX. The framework allowed states to launch applications much faster, and it also invited millions of iPhone users to avoid downloading any content altogether. They only need to tap the switch in the phone settings to activate the notification.
ENX activation is much more convenient, and experts say it seems safer than downloading new applications. It greatly increases the activation rate in states that use it.For example, Hawaii saw its users More than twice ENX will be launched from February to May.
However, the express delivery system does mean that our user data is not accurate. States cannot directly track ENX activations, but instead rely on Apple to obtain their number.
Beyond the numbers
Even if many residents have downloaded an app or turned on that switch in their iPhone settings, the system still needs to be used correctly in order to function in COVID-19 cases. Therefore, we also try to understand how people use these systems.
A kind A recent study It was found that Americans were hesitant to trust digital contact tracking technology. However, this finding is based on surveys conducted before most states even launched their apps. As a representative of the public’s attitudes toward apps in various states in the United States, MIT Technology Review grabbed and analyzed app reviews from the Google Play store. We only checked Google Play reviews (from Android users) for the latest and consistent data. (Most iPhone users can now open notifications without downloading an app.)
Viewing app reviews is not a perfect system. Users who choose to view apps in their state are not a representative sample of people who activate EN—on the contrary, they are users who want to share strong opinions about the technology.
However, this is what we found:
- The average score for most state-level apps is between 3 and 4.
- Michigan has the lowest score at 2.6.
- Washington, DC, California, New York, Delaware, and Massachusetts have the highest scores, exceeding 4.
Many 1-star reviewers seem to have misunderstood how the app in their state works, do not trust the technology, or cannot understand how the app fits into the wider public health system. This shows that for many Americans, even if the application is used technically, it does not work.
Lessons from negative reviews
Poor reviews give us a glimpse of common problems and misunderstandings faced by digital contact tracking systems.
Small glitches make a big difference.
Reviewers have stated over and over again that they were tripped up because they needed an activation code. To help protect privacy, when you test positive for the new coronavirus, you don’t need to enter your name or other identifying information in the app: instead, enter a string of numbers provided to you by the public health department. Some commenters stated that after the test was positive, they did not know where to obtain the activation code, or they encountered an error message. We heard about this issue from developers in other countries.
Some U.S. states and other countries simplify the process by automatically sending codes, but in many cases, users have to wait for the contact tracker to call them. This waiting period reduces trust in the technology and significantly slows down the speed of digital contact tracking.
“Trust” is not just about the application itself. It is broader than that.
Many app reviewers also don’t trust new technologies, governments, or both.A kind Pew Research Center Survey A survey conducted in July 2020 found that 41% of Americans may not talk to public health officials over the phone or text message, and 27% said they are unwilling to share the names of their recent contacts-this is all contact tracing The key element process.
Digital contact tracking faces similar challenges. Some commenters take the protection of their privacy so seriously that they come to the page of their state app to brag about their refusal to download the technology. Many people agree with this reviewer from Pennsylvania: “Open access to my wifi, GPS, and Bluetooth? Crawl. No thanks, Harrisburg.”
Low usage will cause a downward spiral of distrust.
An important aspect of digital contact tracking is that you need to be involved to make it work-at least 15% of community members, But it’s better to be much higherWhen people are not involved, the chances of getting a match will decrease—even if the level of the new coronavirus is high—so the system may not alert a few people do Activate exposure notification.
Some comments even implored other residents in their state to choose to enable exposure notifications, reminding other commenters that the higher the usage rate, the higher the efficiency. This tone seems to be more reminiscent of the Facebook debate than the app store.