1. Department of Epidemiology and Public Health, University College London, London, United Kingdom
2. Centre for Medical Imaging, University College London, London, United Kingdom
3. Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
4. NHS Cancer Screening Programmes, Sheffield, United Kingdom
5. South Tyneside NHS Foundation Trust, South Tyneside School of Medicine, Pharmacy and Health, Durham University, Durham, United Kingdom