1. Division of Musculoskeletal and Dermatological Sciences, The University of Manchester, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
2. Centre for Biostatistics, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
3. Rheumatology Unit, Department of Medicine, Solna, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden