1. Oxford University Hospitals NHS Trust , Oxford OX3 9DU , UK
2. Oxford Medical School , Medical Sciences Divisional Office, , Oxford OX3 9DU , UK
3. University of Oxford , Medical Sciences Divisional Office, , Oxford OX3 9DU , UK
4. Centre for Evidence-Based Medicine , Nuffield Department of Primary Care Health Sciences, , Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG , UK
5. University of Oxford , Nuffield Department of Primary Care Health Sciences, , Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG , UK
6. Department of Internal Medicine, Thames Hospital , MacKay Street, Thames 3500 , New Zealand
7. Bennett Institute for Applied Data Science, Nuffield Department of Primary Care Health Sciences, University of Oxford , Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG , UK
8. Institute of Clinical Sciences, University of Birmingham , Birmingham , UK
9. West Midlands Centre for Adverse Drug Reactions, City Hospital , Birmingham B17 7QH , UK