- Correspondence to Cheryl E Peters, School of Population and Public Health, University of British Columbia, 340—2206 East Mall, Vancouver, British Columbia, Canada V6T1Z3;
- Received April 23, 2014
- Revised May 23, 2014
- Accepted June 6, 2014
- First published June 26, 2014.
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:
- Data supplement 1 - Online supplement
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.