How people used COVID-19 contact tracing apps and why: insights from Belgium’s Coronalert
Co-authors: Sophie Li, Bart Preneel, and Elissa M. Redmiles
During the COVID-19 pandemic, many countries launched contact tracing apps to reduce the spread of the coronavirus. The main objective of these apps is to inform users about possible exposure to people who tested positive for the virus. To ensure the apps’ effectiveness, people must use them appropriately and take action when necessary, such as enabling their phones’ Bluetooth and authorizing the app to share their positive test results. By exploring how and why people use these apps, we can identify pitfalls or risky points throughout the app life cycle. To this end, we interviewed 13 long-term users of Belgium’s contact-tracing app, Coronalert, approximately a year after the pandemic had started. Our analysis yielded several key findings relevant to future health and disaster technologies beyond COVID-19 contact tracing apps.
Key Takeaways:
- The potential role of secondary functionalities in maintaining long-term use. Users repurposed the app into a testing app — for receiving the results of COVID-19 tests — instead of merely using it for contact tracing. Such repurposing encouraged users to a) register the test in the app and b) keep using it.
- Manual steps that require reminders are a crucial pitfall. To link the app to a COVID-19 test result, users must register their test, preferably while getting tested. However, in most cases, users who were not actively asked to register the test — did not do so. Therefore, there is a need to involve the health staff in the design process and to increase users’ independence.
- There is a trade-off between privacy and usefulness. Users might not adopt health apps that do not follow privacy-preserving mechanisms, such as apps that collect more information than the minimum required. However, users expressed their desire for more information about the exposure incidents, therefore, resulting in greater information disclosure.
The Role of Secondary Functionalities
While Coronalert was advertised as a contact tracing app, the users we studied repurposed the app in many ways: as a test results app and for tracking information on Belgium’s COVID-19 situation. In some cases, these secondary uses motivated users to continue using the app.
- With the great challenge of encouraging people to keep using the apps for a long time, we highlight secondary functionalities as a way to promote long-term use of future health and disaster technologies.
- Using the app for secondary functionalities does not prevent the app from reaching its main objectives.
- Beyond long-term use, using a contract tracing app as a “testing app” increased efficacy for contact tracing. Motivation to receive test results served as an additional reason to register the test in the app — an essential step in the notification process.
Pitfall: Manual Test Registration
Drawing on our findings and those from prior work, we synthesize a framework of people’s decision points as they are using contact tracing apps. One of these points is manual test registration, in which people link their test with the app. While people could register the test after getting tested, it was more complicated.
If people were asked to register the test by the testing center staff — they cooperated. However, if they were not, in most cases, they did not register their test.
“If it [registering] is offered to me, I will accept it and do it, but I will not actively go and look for it.” P12
There are two design implications here:
- With health technologies, it is necessary to involve the health staff, and other stakeholders who will be part of the usage process, in the design process. This will ensure an optimal integration with their work.
- It is also important not to lean only on external people, i.e., health staff. Steps should be taken to increase users’ independence, for example, by adding in-app notifications, helping the users to self-remember registering their test, or any other important step, for that matter.
Privacy vs. Usefulness
“It gives information, but it doesn’t give all the information.
You had a contact, but you don’t know when or where or who.
So, all you can do is speculate. And it’s that speculation that could drive you crazy if it was a high risk.” P6
Several participants were willing to have what they considered a more useful app at the cost of having a less privacy-preserving app. While the trade-off between privacy and usefulness is not a new one (think of a navigation app that does not collect your location information), the case of COVID-19 contact tracing app highlights the need to explore people’s perceptions and expectations continuously.
Users referred to gradual changes in their perceptions about the pandemic in general (a sense of fatigue), and about the Coronalert app in particular (less trust in its accuracy). These changes resulted in new needs, such as the need for more information to make informed decisions — to evaluate whether an exposure for which they received a notification was actually high-risk or not.
It is complicated to find the line between “not private enough” and hindering installation, and between “too private” and resulting in users abandoning the technology. Exploring users’ perspective is critical to help us find that line.
To learn more, check out our full paper “Not Only for Contact Tracing: Use of Belgium’s Contact Tracing App among Young Adults” and come chat with us at the coming UbiComp/ISWC 2023.
