1. University College London Hospitals, London, United Kingdom;
2. University College London, London, United Kingdom;
3. Aberdeen Royal Infirmary, Aberdeen, United Kingdom;
4. University of Westminster, London, United Kingdom;
5. University Hospitals Bristol National Health Service Foundation Trust, Bristol, United Kingdom;
6. Royal Cornwall Hospital Trust, Cornwall, United Kingdom;
7. Cardiff and Vale University Hospital, Cardiff, United Kingdom;
8. Guy’s and St. Thomas’ National Health Service Foundation Trust, London, United Kingdom;
9. Basingstoke and North Hampshire National Health Service Trusts, Basingstoke, Hampshire, United Kingdom;
10. Kent and Canterbury Hospitals, Canterbury, Kent, United Kingdom;
11. The Rotunda Hospital, Dublin, Ireland;
12. Sheffield Teaching Hospital National Health Service Trust, Sheffield, United Kingdom;
13. University Hospital Birmingham, Birmingham, United Kingdom; and
14. Manchester Royal Infirmary, Manchester, United Kingdom