Funding for this research was provided by:
Received: 1 September 2017
Accepted: 3 January 2018
First Online: 29 January 2018
Ethics approval and consent to participate
: This study is a registered Clin.ExternalRef removed(NCT02773914) and ethical approval is confirmed (EPN Gbg dn4 899-15).
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.