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. 2009 Aug 11;339:b2880. doi: 10.1136/bmj.b2880

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This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: http://creativecommons.org/licenses/by-nc/2.0/ and http://creativecommons.org/licenses/by-nc/2.0/legalcode.

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graphic file with name stom616250.f1_default.jpg — Fig 1 Flow diagram of exclusions of trials and participants (numbers shown in parentheses)