1. Health Economics Research Centre, University of Oxford, Oxford, UK
2. Centre for Statistics in Medicine, Oxford Clinical Trials Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Oxford, UK
3. School of Health and Related Research (ScHARR), The University of Sheffield, Sheffield, UK
4. Oxford Clinical Trials Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
5. Department of Economics & Laboratory of Applied Economics, University of Western Macedonia, Kastoria, Greece
6. Kennedy Institute, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
7. Faculty of Health and Life Sciences, University of Exeter, Exeter, UK