1. Research Department of Behavioural Science and Health, University College London, London, UK
2. Lungs for Living Research Centre, UCL Respiratory, University College London, London, UK
3. School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
4. Centre for Cancer Prevention, Detection and Diagnosis, Wolfson Institute of Population Health, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK