Müller, D.
Reinig, Y.
Hoffmann, R.
Blank, M.
Welsch, F.
Schweigkofler, U.
Stein, T. http://orcid.org/0000-0002-9970-3528
Article History
Received: 25 September 2017
Accepted: 27 June 2018
First Online: 6 July 2018
Compliance with ethical standards
:
: T. Stein has received payment for instructional courses. Other authors declare that they have no conflict of interest.
: The institutional ethics committee approved all data-collection and randomising procedures (clinical trial registry number: FF 42/2011).
: All subjects provided informed consent.