Imperial College London - National Heart and Lung Institute, Imperial College London - National Heart and Lung Institute, Golden Jubilee National Hospital - Department of Thoracic Surgery, Golden Jubilee National Hospital - Department of Thoracic Surgery, Golden Jubilee National Hospital - Department of Thoracic Surgery, University of Leicester - Institute for Lung Health, Northern General Hospital, Royal Brompton Hospital - Department of Thoracic Surgery, affiliation not provided to SSRN, Golden Jubilee National Hospital - Department of Thoracic Surgery, University of Leicester - Institute for Lung Health, Government of the United Kingdom - St Bartholomew's Hospital, Northern General Hospital, Brunel University London - Department of Health Sciences, King’s College London, University of Leicester - Institute for Lung Health, University of Leicester - Institute for Lung Health, Northern General Hospital, Government of the United Kingdom - St Bartholomew's Hospital, Imperial College London - National Heart and Lung Institute, Imperial College London - National Heart and Lung Institute and Independent