1 MRC Integrative Epidemiology Unit and School of Population Health Sciences, University of Bristol, Bristol BS2 8BJ, UK; Department of Paediatric Rheumatology, Bristol Royal Hospital for Children, Bristol, UK.
2 School of Translation Health Sciences, University of Bristol, Bristol BS2 8BJ, UK; Department of Paediatric Rheumatology, Bristol Royal Hospital for Children, Bristol, UK. Electronic address: a.ramanan@bristol.ac.uk.