Competing interests
Simon D Kyle declares research funding from the NIHR HTA programme (references: 16/84/01 and 12/87/61), Efficacy and Mechanism Evaluation programme (EME) (reference: 131789), and the NIHR Oxford Health Biomedical Research Centre; and non-financial support from Big Health Ltd in the form of no cost access to the digital sleep improvement programme, Sleepio, for use in clinical research (outside the submitted work). Paul Aveyard is NIHR senior investigator and declares research funding from NIHR HTA, NIHR Oxford Health Biomedical Research Centre, and NIHR Oxford and Thames Valley Applied Research Collaboration. Aloysius Niroshan Siriwardena declares research funding from the Wellcome Trust, NIHR HTA, Research for Patient Benefit programme, and Health and Social care Delivery Research programme. Ly-Mee Yu declares research funding from NIHR HTA. Peter Bower declares research funding from NIHR HTA. Leonie Maurer declares funding from NIHR Oxford Health Biomedical Research Centre and consultancy fees from Mementor DE GmbH, outside the submitted work. Colin A Espie declares research funding from NIHR HTA, EME, and NIHR Oxford Health Biomedical Research Centre, and is co-founder of and shareholder in Big Health Ltd, a company that specialises in the digital delivery of cognitive behavioural therapy for sleep improvement (the Sleepio programme), outside the submitted work. Dimitri Gavriloff declares consultancy fees from Big Health Ltd and Idorsia Pharmaceuticals Ltd, and is a previous salaried employee of Big Health Ltd. The other authors have declared no competing interests.