Published on in Vol 20, No 2 (2018): February
1 Community and Primary Care research group, Plymouth University Peninsula Schools of Medicine & Dentistry, Plymouth, United Kingdom
2 UK Centre for Tobacco and Alcohol Studies, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
3 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom
4 Health Services and Policy Research Group, University of Exeter Medical School, Exeter, United Kingdom
*these authors contributed equally