Direct Measurements of Smartphone Screen-Time: Relationships with Demographics and Sleep

Area of Science:

• Digital Health
• Sleep Science
• Human-Computer Interaction

Background:

• Smartphones are integral to daily life, yet objective data on usage frequency and its correlation with demographics and sleep quality is limited.
• Previous research relied on self-reported data, potentially introducing bias.

Purpose of the Study:

• To objectively measure smartphone screen-time in adults.
• To identify demographic and health factors associated with increased screen-time.
• To investigate the relationship between smartphone screen-time and sleep quality.

Main Methods:

• Cross-sectional analysis of 653 adults from the Health eHeart Study.
• Objective measurement of smartphone screen-time using a dedicated application.
• Surveys collected data on demographics, medical history, and sleep quality (using PSQI).

Main Results:

• Median total screen-time was 38.4 hours over 30 days; median average screen-time was 3.7 minutes/hour.
• Younger age and Black/Other race were associated with higher average screen-time.
• Increased screen-time correlated with shorter sleep duration, worse sleep efficiency, and longer sleep onset latency, particularly when used during bedtime.

Conclusions:

• Objective smartphone screen-time is substantial and varies by age and race, suggesting cultural influences.
• Smartphone use, especially before sleep, is linked to negative impacts on sleep quality and efficiency.
• While causation is not established, the findings highlight potential risks of screen exposure on sleep.