Title : Barriers and facilitators for adoption of exposure notification applications implemented during the COVID-19 pandemic: A systematic review

Background: During the COVID-19 pandemic, Public Health Authorities (PHAs) adopted exposure notification (EN) systems—built on an application programming interface created in collaboration with Apple and Google, known as the Google and Apple Exposure Notification (GAEN) system—as a supplementary tool to traditional contact tracing (TCT). These systems informed individuals of a potential exposure to the SARS-CoV-2 virus. We aimed to identify the barriers and facilitators associated with user adoption to maximize the effectiveness of EN systems.  

Methods: We developed a systematic review protocol informed by the principles of the Cochrane methods, and searched PubMed, Embase, Web of Science, and the ProQuest - PAIS Index to identify studies concerning the barriers and facilitators of EN system adoption. Our search focused on empirical studies, including qualitative, quantitative, and mixed-methods research, that reported on the user-level, technical, or systemic factors contributing to EN uptake. Two reviewers independently screened abstracts and full-text articles against predefined eligibility criteria, extracted relevant data, and synthesized the evidence base from incorporated studies.

Results: We identified 2224 peer-reviewed studies, of which we removed 866 duplicates, 1148 references during the abstract screening phase, and 119 during full text screenings. This yielded a total of 72 references for extraction. All studies indicated the importance of adoption and use of the system, given that the system’s effectiveness is dependent on people using the application to report positive COVID-19 diagnoses, thereby initiating anonymous exposure alerts. The major factors contributing to app adoption rates included user characteristics, perceived benefits of app use, privacy concerns, governmental mistrust, and communication. Perceived personal and community benefit, trust in political and medical institutions, and effective public communication positively influenced adoption rates. By contrast, common barriers included technical issues such as device incompatibility and notification delays, as well as digital literacy gaps and limited smartphone access among marginalized groups.  

Conclusion: Multiple EN systems globally have been shown to face similar barriers and facilitators; however, through further development of the infrastructure surrounding the implementation of such applications and a dedicated focus on strategies aimed at increasing adoption, GAEN-based applications could successfully supplement manual contact tracing for infectious diseases with similar transmission pathways to the SARS-CoV-2 virus. For future EN applications, emphasis should be placed on the importance of public outreach programs to increase user adoption and adherence, thereby increasing the overall epidemiological impact of the EN systems.  

Amaan Ali Mohammed is a current first-year undergraduate student at the University of California, Riverside, pursuing a Bachelor of Science in Cell, Molecular, and Developmental Biology. He is a current student intern at the University of California, San Francisco, Institute for Global Health Sciences.