- Correspondence to Emma Victoria Beard, Epidemiology and Public Health, UCL, London WC1E 6BT, UK;
- Received October 19, 2018
- Revised February 27, 2019
- Accepted March 18, 2019
- First published August 7, 2019.
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.