. 2014 Jun 10;15:200. doi: 10.1186/1471-2474-15-200
Copyright © 2014 Petersen et al.; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.
Figure 1.
Flow chart of the study design.