Supplementary files
Online appendices
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Files in this Data Supplement:
- Online appendix 9 - Online appendix 9
- Online appendix 10 - Online appendix 10
- Online appendix 11 - Online appendix 11
- Online appendix 12 - Online appendix 12