1 National Institute for Health and Care Excellence, Manchester M1 4BT, UK.
2 Rheumatology Research group, Department of Musculoskeletal Biology I, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool L69 3BX, UK.
3 Shropshire Community Health NHS Trust, Shrewsbury SY3 8XL, UK.
4 Department of Primary Care and Health Sciences, Keele University, Staffordshire ST5 5BG, UK.
5 National Institute for Health and Care Excellence, Manchester M1 4BT, UK Gabriel.Rogers@nice.org.uk.