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. 2014 Aug 1;14:779. doi: 10.1186/1471-2458-14-779

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© Laws et al.; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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Summary of search strategy and articles identified in the review. ¹Protocol papers or papers reporting long term follow up for primary studies included in the review.