Text and Data Mining valid from 2019-11-21
Received: 23 August 2019
Accepted: 29 October 2019
First Online: 21 November 2019
Ethics approval and consent to participate
: The ethical approvement consent to participate was provided by the local ethical committee.The consent to participate is not applicable considering the fact that we used administrative data.
: The manuscript does not contain any individual person’s data. The consent for publication is not applicable.
: The authors declare that they have no competing interests.