Al-Hakim, S.
Schaumann, A.
Tietze, A.
Schulz, M.
Thomale, U-W
Article History
Received: 6 August 2019
Accepted: 20 September 2019
First Online: 25 October 2019
Compliance with ethical standards
: The study received approval from the institutional ethics committee (EA2/132/17).