- Correspondence to Dr Nancy L Fleischer, Center for Social Epidemiology and Population Health, Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA;
- Received 4 October 2017
- Revised 13 February 2018
- Accepted 14 February 2018
- Published online 8 March 2018.
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.