Received: 19 March 2019
Accepted: 25 June 2019
First Online: 10 July 2019
Ethics approval and consent to participate
: This study was conducted according to the principles of the Declaration of Helsinki (version 59, 2008) and in accordance with the Medical Research Involving Human Subjects Act. The study was approved by the Medical Ethics Committee of the Medical University Center of Leiden. All subjects provided written informed consent.
: “Not applicable”.
: The authors declares that they have no competing interests.