[1] Univ Oxford, Hlth Econ, Oxford, England
[2] Univ Oxford, Nuffield Dept Primary Care Hlth Sci, Oxford, England
[3] Univ Oxford, Ctr Stat Med, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Oxford Clin Trials Res Unit, Oxford, England
[4] Univ Oxford, Kadoorie Ctr, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Trauma & Orthopaed, Oxford, England
[5] Univ Oxford, Kadoorie Ctr, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Oxford, England
[6] Univ Oxford, Kadoorie Ctr, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, OrthopaedicTrauma Surg Oxfor Trauma, Oxford, England