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Acceptability of app-based contact tracing for COVID-19: Cross-country survey evidence

Our take —

Early evidence from a large online survey conducted in four European countries and the United States suggests a high willingness to install or keep a digital contact tracing application on a mobile device, with few differences across sub-populations (i.e., age, gender) and countries. Additional corroboration of these results, through end-user pilot tests and other demonstration activities, is required to determine actual acceptability of a digital contact tracing app. This manuscript was a preprint at the time of review, and was not yet subjected to the peer review process.

Study design


Study population and setting

The objective of the study was to determine the acceptability and willingness to use a mobile phone application (“app”) facilitating digital contact tracing for COVID-19. The investigators implemented an online survey with a socio-demographically representative sample of adults (N = 5,995) in four European countries (France, Germany, Italy, and the United Kingdom) and the United States. The surveys evaluated user acceptance of the app under different installation methods (voluntary installation or automatic installation), comparing across participant socio-demographic characteristics, political affiliations/beliefs, and COVID-19 epidemic properties in participants’ country of residence.

Summary of Main Findings

Across countries, three-fourths (75%) of respondents expressed willingness to download the app onto their mobile phones, and over two-thirds (68%) reported desire to keep the app installed on their devices if automatically downloaded. Self-reported reasons for supporting the app included a desire to protect friends/family, obligations towards community, and perceived effectiveness of stopping the spread of COVID-19. Other factors associated with app support included carrying a cellphone regularly, having a chronic health condition, and higher self-reported trust in the government. Sources of opposition for using the app revolved around concerns regarding government surveillance and phone security. Support for both voluntary and automatic installation was higher among participants in the United Kingdom, Italy, and France compared to Germany and the United States, respectively. No differences in app support across socio-demographic characteristics (i.e., age, gender) or among participants in countries with different COVID-19 mortality profiles were observed.

Study Strengths

The investigators included questions gauging support for digital contact tracing applications under different installation scenarios. Participant recruitment in multiple countries also helps generalize the findings to populations in different epidemic contexts, and understand user preferences in different settings. The investigators also reproduced their analyses using different statistical models (with different parameters and underlying assumptions) in order to corroborate the quantitative findings.


Fewer than two-thirds (59%) of sampled individuals were included following the online comprehension check prior to survey administration, which is highly suggestive of response and selection biases that may reduce the representativeness of survey participants. The survey did not include additional behavioral questions that may influence user acceptance of and willingness to use a digital contact tracing app, including self-reported adherence to physical distancing ordinances and perceived risk of COVID-19 infection. Lastly, the authors measured interest in a hypothetical digital contact tracing app, which may not align with actual user behavior towards the mobile app (particularly since the details and characteristics of an app were not available to participants at the time of survey administration).

Value added

This is among the first studies to measure willingness to use digital contact tracing apps in a large population-based sample recruited from various high-income countries.