Digital Phenotypes for Understanding Individuals' Compliance With COVID-19 Policies and Personalized Nudges: Longitudinal Observational Study

BackgroundGovernments promote behavioral policies such as social distancing and phased reopening to control the spread of COVID-19. Digital phenotyping helps promote the compliance with these policies through the personalized behavioral knowledge it produces. ObjectiveThis study investigated the value of smartphone-derived digital phenotypes in (1) analyzing individuals’ compliance with COVID-19 policies through behavioral responses and (2) suggesting ways to personalize communication through those policies. MethodsWe conducted longitudinal experiments that started before the outbreak of COVID-19 and continued during the pandemic. A total of 16 participants were recruited before the pandemic, and a smartphone sensing app was installed for each of them. We then assessed individual compliance with COVID-19 policies and their impact on habitual behaviors. ResultsOur results show a significant change in people’s mobility (P