App use during the sleep period and next day activity

Abstract Human performance during the day is highly sensitive to the sleep quality obtained on the prior night. Although uninterrupted sleep is widely recommended, many people now spend time on mobile phone apps during their sleep period. While scholars have recently investigated the influence of evening app use on sleep, the influence of smartphone app use after sleep onset on behavior the following day is not well understood. Here, we address this gap. Drawing on a global dataset from 120 countries comprising 41374 individuals and 11 million nightly observations collected by smartphones and wristbands from 2015-2018, we study the real-world relationships between app use during the sleep period and next day digital and physical behavior. We find that a large majority use mobile apps during the sleep period, over a quarter of adults regularly do so, and that the prevalence, rate, and duration are increasing on average, across sex and age groups, and in most global regions. Social media comprises about half of sessions while gaming occupies the most time. Even brief social media and gaming app usage during the sleep period is associated with abrupt within-individual increases in app use of the same category the following day and workday, along with reduced physical activity. Next day activity disruptions scale with longer usage, with social media use during the sleep period associated with larger reductions in physical activity than from gaming or video app use of equal dose. Our study suggests that smartphone app use after sleep onset precedes delayed behavioral changes in a dose response relationship, globally.