Received: 18 December 2017
Accepted: 15 May 2018
First Online: 31 May 2018
Ethics approval and consent to participate
: All participants of the study gave written informed consent. Participation was voluntary and confidentiality was guaranteed through anonymous data gathering. Indeed, this study has been approved by the Ethics Committee at the Research Division of the Ministry of Health in Tehran (Project number: 93–03–103-26,804-144,653) and by the ethic commission of the medical faculty of the RWTH Aachen University (EK176/11).
: The authors declare that they have no competing interests.
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