An umbrella review synthesising published systematic review evidence for self-harm and suicidality among patients diagnosed with an eating or feeding disorder.

With constant network connectivity and a wide range of applications, smartphones have become integral to daily life. Young adults aged 18–24 have the highest smartphone ownership rates globally, reaching 100% in Singapore. University students, in particular, represent a critical population for digital health research, as they experience high academic demands, increasing independence, and rising mental health challenges. These factors may contribute to unhealthy lifestyle behaviors, with prevalence estimates of smartphone addiction among university students ranging from approximately 28% to 80%. The pervasive use of smartphones has raised concerns about both physical and mental health. Excessive smartphone screen time (SST) has been associated with insufficient sleep, physical inactivity, altered cortical processes, and musculoskeletal disorders related to prolonged poor postures. Furthermore, smartphone use, particularly for social media, has been linked to poorer mental well-being, higher levels of anxiety and depression among young people, and disruptions to essential daily routines like studying and socializing. However, much of the existing evidence on SST and its health effects is based on self-reported data, which is subject to recall bias, social desirability bias, and incomplete reporting, particularly for habitual behaviors that occur frequently and often go unnoticed by individuals. Studies comparing self-reported and objectively measured SST have revealed significant discrepancies, with self-reports often underestimating actual usage. While some research has attempted to move toward objective measurement, many prior studies have relied on limited or indirect data sources, such as static screenshots of device “Screen Time” summaries, single application logs, or computer activity logs. Those using mobile tracking applications mainly report daily total screen time, lack analysis of time of day or day type (weekday/weekend) patterns, or focus on a single usage indicator without integrating duration, frequency, and app-level behaviors. Recent advances in passive smartphone monitoring applications allow for the continuous, timestamped collection of screen state and app usage, enabling high-granularity assessment of smartphone use in real-world settings. Such data offer several advantages: they minimize reporting bias, enable examination of usage frequency and timing across the 24-h day, and allow differentiation of behaviors by app type and context. Importantly, evidence suggests that these dimensions, including when screens are used, how often they are checked, and for what purposes, may be more relevant to health outcomes than total daily screen time alone. Despite these advantages, most objective studies remain limited in scope. To our knowledge, no study has comprehensively characterized high-granularity 24-h smartphone usage patterns, combining screen-state duration, use frequency, and app usage to examine temporal and contextual variation among university students.