Received: 30 August 2018
Accepted: 16 October 2019
First Online: 28 October 2019
Ethics approval and consent to participate
: Since our analysis was restricted to non-identifiable (anonymous) patient data, we refrained from consulting the local ethics committee, whose responsibility is limited to research based on identifying patient data in accordance with Section 15 of the code of conduct of the national (and Bavarian) professional medical association. The Data Protection Officer of the university hospital in Erlangen approved our planned investigation after informal consultation. Due to the anonymity of our data, asking patients for consent to participate was neither required nor feasible.
: Not applicable.
: The authors declare that they have no competing interests.