1. Norwich Medical School, University of East Anglia, Norwich, UK
2. Bristol Heart Institute, University of Bristol, School of Clinical Sciences, Bristol, UK
3. Health Economics Research Centre, Nuffield Department of Population Health, University of Oxford, Oxford, UK
4. Centre of Statistics in Medicine, Botnar Research Centre, University of Oxford, Oxford, UK
5. Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
6. Department of Anaesthesiology and Intensive Care, Medical University of Silesia, Katowice, Poland
7. Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York Presbyterian Hospital, New York, NY, USA