Development and Evaluation of a Digital Sleep Intervention (SleepWise) aimed at Adolescents

Student thesis: Doctoral Thesis


While it is recommended that adolescents gain 8-10 hours of sleep per night, most adolescents do not sleep for the recommended amount. Poor sleep among adolescents is associated with weight gain, reduced physical activity, increased risk-taking behaviours, and increased levels of depression and anxiety, making this a significant public health concern. Current interventions targeting adolescent sleep are often reported by users as being non-interactive and do not address age-specific needs. They are also often time-consuming and lack a theoretical foundation. Innovative sleep interventions, that apply a systematic and evidence-based approach to intervention development, are needed.
This PhD aimed to design, develop, and evaluate the feasibility of an evidence-theory-and-person-based digital intervention targeted at adolescents, using the Person-Based Approach (PBA) to intervention development. This was achieved by conducting the following studies:
Study 1: involved the development of an evidenced-based digital (website) prototype intervention (SleepWise). A scoping review was conducted to identify effective intervention ingredients, which were then mapped to key features of the intervention (guiding principles). From this, causal and logic models were developed, bringing together evidence-based barriers and facilitators and the necessary intervention components.
Study 2: involved the optimisation of the prototype intervention, to ensure that it was as feasible and acceptable as possible. Think-aloud interviews were undertaken with adolescents to explore perceptions of the prototype intervention. Participant feedback provided insight into the likely intervention implementation and identified features of relevance, or influence, on participant engagement.
Study 3: involved two 2-arm randomised controlled trials to test the feasibility of the optimised intervention. A process evaluation was carried out to investigate usage with and feedback about the intervention.
This PhD highlights the utility of the PBA to intervention development, and demonstrates that SleepWise is a feasible digital intervention to target adolescent sleep, and a pragmatic solution to an important public health issue.
Date of Award27 Apr 2021
Original languageEnglish
Awarding Institution
  • University of Winchester
SupervisorDebra Gray (Supervisor), Margaret Husted (Supervisor) & Ana Aznar (Supervisor)


  • Digital Health Interventions
  • Sleep
  • Adolescence
  • Behaviour Change
  • Person-Based Approach

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