Transforming a Pandemic Tool Into a Public Health Asset: Modified Delphi Study.

Background: During the COVID-19 pandemic, over 100 countries successfully deployed smartphone-based exposure notification (EN) apps alongside conventional contact tracing to mitigate the transmission of SARS-CoV-2. These systems enabled millions of COVID-19-positive individuals to anonymously alert community members of a potential exposure. Although evidence on EN program implementation is limited, leveraging expertise from public health professionals, academics, and global implementers from various disciplines can contribute to addressing this research gap. Objective: This study aimed to explore barriers and facilitators to adoption, identify optimal use cases for these tools, and understand how advancements in technology and policy might maximize EN utility for mitigating other infectious outbreaks. Methods: We used the Delphi method to develop a comprehensive online survey comprising closed-ended and open-ended questions. We considered consensus was reached when at least 75% of respondents selected "agree" or "strongly agree" for an item or statement. More than 30 global EN experts known to the investigators were invited to participate in the survey, and those who participated were asked to nominate or recruit others deemed eligible via a peer-to-peer method. We used descriptive and content analyses to summarize key findings from the survey. We invited the same experts to attend virtual focus groups to further probe their insights into the survey findings. Results: Twenty-two experts from 6 countries, including 10 experts from the United States, representing 3 continents, participated. Respondents were involved in the implementation of various EN technologies that encompassed varying levels of integration with existing public health agencies' infrastructure. Consensus was reached concerning the development of additional functionalities of the system, such as the ability for users to self-report a positive result from a SARS-CoV-2 at-home test, receive additional public health information from the app (ie, information on testing and social services), and receive general venue-based notifications concerning superspreader events. Other items that reached consensus included how the tool could be used for additional epidemiological purposes, such as expanding the technology to other airborne diseases, and the need for integration with surveillance data streams to augment analytics and forecasting. Conclusions: Global EN systems have the potential to be optimized for public health emergencies beyond COVID-19 and can be used as epidemiological surveillance tools in future disease outbreaks. Decision-makers and experts should revise existing protocols and seek to incorporate new functionality to alleviate the disease burden on both users and public health agencies.