Best Practice Guidance for Digital Contact Tracing Apps: A Cross-disciplinary Review of the Literature

Abstract

Background Digital contact tracing apps have the potential to augment contact tracing systems and disrupt COVID-19 transmission by rapidly identifying secondary cases prior to the onset of infectiousness and linking them into a system of quarantine, testing, and health care worker case management. The international experience of digital contact tracing apps during the COVID-19 pandemic demonstrates how challenging their design and deployment are. Objective This study aims to derive and summarize best practice guidance for the design of the ideal digital contact tracing app. Methods A collaborative cross-disciplinary approach was used to derive best practice guidance for designing the ideal digital contact tracing app. A search of the indexed and gray literature was conducted to identify articles describing or evaluating digital contact tracing apps. MEDLINE was searched using a combination of free-text terms and Medical Subject Headings search terms. Gray literature sources searched were the World Health Organization Institutional Repository for Information Sharing, the European Centre for Disease Prevention and Control publications library, and Google, including the websites of many health protection authorities. Articles that were acceptable for inclusion in this evidence synthesis were peer-reviewed publications, cohort studies, randomized trials, modeling studies, technical reports, white papers, and media reports related to digital contact tracing. Results Ethical, user experience, privacy and data protection, technical, clinical and societal, and evaluation considerations were identified from the literature. The ideal digital contact tracing app should be voluntary and should be equitably available and accessible. User engagement could be enhanced by small financial incentives, enabling users to tailor aspects of the app to their particular needs and integrating digital contact tracing apps into the wider public health information campaign. Adherence to the principles of good data protection and privacy by design is important to convince target populations to download and use digital contact tracing apps. Bluetooth Low Energy is recommended for a digital contact tracing app's contact event detection, but combining it with ultrasound technology may improve a digital contact tracing app's accuracy. A decentralized privacy-preserving protocol should be followed to enable digital contact tracing app users to exchange and record temporary contact numbers during contact events. The ideal digital contact tracing app should define and risk-stratify contact events according to proximity, duration of contact, and the infectiousness of the case at the time of contact. Evaluating digital contact tracing apps requires data to quantify app downloads, use among COVID-19 cases, successful contact alert generation, contact alert receivers, contact alert receivers that adhere to quarantine and testing recommendations, and the number of contact alert receivers who subsequently are tested positive for COVID-19. The outcomes of digital contact tracing apps' evaluations should be openly reported to allow for the wider public to review the evaluation of the app. Conclusions In conclusion, key considerations and best practice guidance for the design of the ideal digital contact tracing app were derived from the literature.

I use a COVID-19 contact-tracing app. Do you? Regulatory focus and the intention to engage with contact-tracing technology

“…In a related vein, there is evidence that people also have concerns about information security ( O'Connell et al., 2021 ). Security flaws both in the design and implementation of contact-tracing apps may put personal data at risk.…”

Digital Contact Tracing and COVID-19: Design, Deployment, and Current Use in Italy

“…In addition, on these aspects, the scientific literature is supporting us and could be extended to the Italian DCT experience: Some works are moving towards the definition of protocols for the correct identification of the factors [ 44 ]. Some authors have focused on the desirable requirements that a DCT app must have to be successful and have made them explicit [ 14 ]. Other authors went to the field to review the reports on the app stores relating to these apps [ 8 ] to understand what the users were not satisfied with.…”

“…Some authors have focused on the desirable requirements that a DCT app must have to be successful and have made them explicit [ 14 ].…”

“…A lot of both technological and medical knowledge has been collected. There are now studies, such as [ 14 ], which derive and summarize best practices for the design of the ideal digital contact tracing apps.…”

Appraisal of a Contact Tracing Training Program for COVID-19 in Greece Focusing on Vulnerable Populations

“…The use of technology in the form of digital applications, platforms and artificial intelligence systems has been proposed as a possible strategy to increase the coverage and effectiveness of contact tracing [25][26][27][28][29][30]. However, issues around privacy, administrative organisation, legal, ethical and cultural considerations have emerged as hurdles to the wider use of technological platforms that could contribute to the effectiveness of contact tracing services [31][32][33][34][35][36].…”