1. 1NIHR Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, UK
2. 2Test Evaluation Research Group (TERG), Institute of Applied Health Research, University of Birmingham, Birmingham, UK
3. 3Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands
4. 4Department of Endocrinology, Leiden University Medical Center, Leiden, the Netherlands
5. 5Birmingham Acute Care Research Group (BACR), Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
6. 6Paediatric Intensive Care Unit, Birmingham Women & Children’s Hospital NHS Foundation Trust, Birmingham, UK