. Author manuscript; available in PMC: 2018 Aug 18.
Published in final edited form as: Annu Rev Public Health. 2017 Jan 11;38:241–257. doi: 10.1146/annurev-publhealth-031816-044232
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 (CC-BY-SA) International License, which permits unrestricted use, distribution, and reproduction in any medium and any derivative work is made available under the same, similar, or a compatible license. See credit lines of images or other third-party material in this article for license information.