Received: 23 March 2019
Accepted: 24 May 2019
First Online: 31 May 2019
Ethics approval and consent to participate
: All research was carried out in compliance with the Helsinki Declaration. This study was approved by the Ethics Committee of Wroclaw Medical University (number KB-783/2017). The data were analyzed anonymously and retrospectively on the basis of medical records. The authors did not have access to any identifying patient information and did not have any direct access to the study participants.
: Not applicable.
: The authors declare that they have no competing interests.