Funding for this research was provided by:
Received: 19 September 2018
Accepted: 2 January 2019
First Online: 16 January 2019
Ethics approval and consent to participate
: Written informed consent was obtained from all participants according to the Declaration of Helsinki. The study was approved by the local medical research ethics committee of Erasmus Medical Centre Rotterdam, the Netherlands (MEC-2012-549).
: Not applicable.
: The authors declare that they have no competing interests.
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