The Study of Sleep Hygiene & Health (SSHH) is a citizen-science research project involving King’s College London and South London and Maudsley NHS Foundation Trust. It investigates how smartphone use, particularly before bedtime, relates to sleep quality, duration and overall sleep hygiene. Social media, messaging, gaming and other digital activities are part of everyday life, yet their different relationships with sleep remain poorly understood. The study combines smartphone usage data, wearable measurements, daily questionnaires and cognitive assessments to examine these relationships in real-world settings. Open to people aged 13 and above, it aims to generate evidence that can inform healthier digital habits and sleep recommendations.

Objectives

SSHH investigates whether increased screen time before bedtime is associated with delayed sleep onset, shorter sleep duration and reduced sleep efficiency. It also examines differences between application categories, including social media, gaming and productivity, and compares sleep patterns across age groups. Longitudinal monitoring over several months will help researchers identify how digital behaviour and sleep vary over time. Short daily questionnaires assess sleep and mood, while Cognitron cognitive tasks explore relationships between smartphone use, sleep, attention, memory and thinking.

Challenge

Smartphone habits and sleep patterns fluctuate from day to day, making them difficult to understand through occasional questionnaires or laboratory assessments alone. Understanding the relationship between digital activity and sleep requires combining detailed phone-use information with physiological measurements and participant-reported experiences. Sustaining regular overnight wearable use, daily questionnaires and cognitive testing over several months also creates participation and data-completeness challenges. The study must bring together different data streams while supporting participants across a broad age range.

RADAR-base Solution

SSHH uses the RADAR-base study enrolment infrastructure to support remote participation and multimodal data collection. Participants install two secure research apps and contribute information about smartphone interactions, application usage and screen habits. Wearable devices provide complementary measurements of sleep, heart rate and movement, including overnight monitoring. Daily app-based questionnaires capture self-reported sleep and mood, while Cognitron tasks assess cognitive performance. Together, these active and passive measurements create a longitudinal dataset connecting everyday digital behaviour with sleep and cognitive functioning.

Impact

SSHH could improve understanding of how the timing, duration and type of smartphone activity relate to sleep health and everyday cognitive functioning. Combining passive sensing with participant-reported experiences may provide a more detailed picture than retrospective questionnaires alone. The findings could inform evidence-based screen-time guidance, digital wellbeing initiatives and personalised sleep hygiene recommendations. Participants will also receive a summary of their own sleep data at the end of the study, supporting greater awareness of their individual sleep patterns.