Text and Data Mining valid from 2018-07-13
Received: 9 July 2017
Accepted: 1 July 2018
First Online: 13 July 2018
Ethics approval and consent to participate
: This study (PB_2016–01264) was approved by the responsible ethics board of the Kantonale Ethikkommission des Kanton Zurich and carried out in accordance with the Declaration of Helsinki, taking into consideration local regulations and standards.
: Not applicable.
: The authors declare that they have no competing interests.
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