1. Social Policy Research Unit, University of York, York, UK
2. York Trials Unit, Department of Health Sciences, University of York, York, UK
3. Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
4. Centre for Reviews and Dissemination, University of York, York, UK
5. The Children’s Sleep Charity, Doncaster, UK
6. Department of Respiratory Medicine, Sheffield Children’s NHS Foundation Trust, Sheffield, UK
7. Blenheim House Child Development Centre, Blackpool Teaching Hospitals NHS Foundation Trust, Blackpool, UK