1. Department of Critical Care medicine; University Hospital of Birmingham NHS trust; Birmingham UK
2. Department of Epidemiology; Biostatistics and Occupational Health; McGill University; Montreal QC Canada
3. Department of Neurology; University Hospital of Birmingham NHS trust; Birmingham UK
4. Department of Critical Care medicine; Queen's University; Belfast UK
5. Institute of Inflammation and Ageing; University of Birmingham; Birmingham UK
6. Institute of Clinical Sciences; University of Birmingham; Birmingham UK
7. School of Infection and Immunity; University of Birmingham; Birmingham UK