- Correspondence to Dr Lion Shahab, Department of Epidemiology & Public Health, University College London, 1–19 Torrington Place, London WC1E 6BT, UK;
- Received December 13, 2014
- Accepted March 31, 2015
- First published April 17, 2015.
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.