- Correspondence to Professor Yvonne Kelly, Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, UK,
- Received January 8, 2016
- Accepted August 31, 2016
- First published September 26, 2016.
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.