1. NHS Grampian, Aberdeen Royal Infirmary, Aberdeen, UK
2. Health Services Research Unit, University of Aberdeen, Aberdeen, UK
3. Medical Statistics Team, University of Aberdeen, Aberdeen, UK
4. Health Economics Research Unit, University of Aberdeen, Aberdeen, UK
5. Birmingham Women’s NHS Foundation Trust, Birmingham Women’s Hospital, Birmingham, UK
6. Countess of Chester Hospital NHS Foundation Trust, Chester, UK
7. NHS Greater Glasgow and Clyde, Southern General Hospital, Glasgow, UK
8. Hull and East Yorkshire Hospitals NHS Trust, Castle Hill Hospital, Cottingham, UK
9. Usher Institute of Population Health Sciences & Informatics, University of Edinburgh, Edinburgh, UK
10. Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK