(c)
The  Author  2017.  Published  by  Oxford  University  Press  on  behalf  of  the  European  Public  Health  Association.
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Except where otherwise noted, this item's license is described as (c) The Author 2017. Published by Oxford University Press on behalf of the European Public Health Association. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com