- Received February 10, 2015
- Revised April 20, 2015
- Accepted April 23, 2015
- First published July 8, 2015.
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.
- Data supplement 1 - Online Appendix A
- Data supplement 2 - Online Appendix B
- Data supplement 3 - Online Appendix C
- Data supplement 4 - Online Appendix D
- Data supplement 5 - Online Appendix E
- Data supplement 6 - Online Appendix F
- Data supplement 7 - Online Appendix G
- Data supplement 8 - Online Appendix H
- Data supplement 9 - Online Appendix I
- Data supplement 10 - Online Appendix J
- Data supplement 11 - Online Appendix K
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