1. Department of Health Sciences and Hull York Medical School, University of York, York, UK
2. Department of Health Sciences, University of York, York, UK
3. York Trials Unit, University of York, York, UK
4. Institute of Population Health, University of Liverpool, Liverpool, UK
5. School of Education, University of Durham, Durham, UK
6. NIHR Alder Hey Clinical Research Facility, Alder Hey Children’s Hospital NHS Foundation Trust, Liverpool, UK
7. NIHR School for Primary Care Research, University of Manchester, Manchester, UK
8. Centre for Medical Statistics and Health Evaluation, University of Liverpool, Liverpool, UK
9. School of Design, Clothworkers’ Central, University of Leeds, Leeds, UK