Received: 9 May 2019
Accepted: 16 July 2019
First Online: 24 July 2019
Ethics approval and consent to participate
: The study was approved by the ethics committee for clinical research of the health area of Gipuzkoa (Spain). Informed consent was waived due to the retrospective nature of the study.
: Not applicable.
: The authors declare that they have no competing interests.