1 The James Cook University Hospital, Middlesbrough TS4 3BW, UK Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7HE, UK York Trials Unit, Department of Health Sciences, University of York, York YO10 5DD, UK amar.rangan@york.ac.uk.
2 School of Health and Social Care, Teesside University, Middlesbrough TS1 3BX, UK.
3 York Trials Unit, Department of Health Sciences, University of York, York YO10 5DD, UK.