Text and Data Mining valid from 2019-01-05
Received: 24 July 2018
Accepted: 11 December 2018
First Online: 5 January 2019
Ethics approval and consent to participate
: The study was approved by the medical ethics committee of the Leiden University Medical Center, who waived the need for individual informed consent as this was a purely observational study.
: Not applicable.
: The authors declare that they have no competing interests.
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