Text and Data Mining valid from 2019-05-14
Received: 19 July 2018
Accepted: 6 May 2019
First Online: 14 May 2019
Ethics approval and consent to participate
: The study protocol was approved by the local ethics committee on Medical University of Lodz (RNN/126/07/KE).
: Not applicable.
: The authors declare that they have no competing interests.