Funding for this research was provided by:
Pomeranian Medical University in Szczecin
Article History
Received: 1 May 2020
Revised: 14 July 2020
Accepted: 3 August 2020
First Online: 14 August 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: For this type of study formal consent is not required.
: As this was a retrospective analysis of the studies that had been published in the past, no consent to participate was necessary.
: The authors of this study grant the Publisher the sole and exclusive license of the full copyright.