Funding for this research was provided by:
European Commission (QLK6-CT-2001-00360)
refonet – Rehabilitation Research Network of the German Pension Fund Rhineland (14006)
Article History
Received: 23 October 2018
Accepted: 30 June 2019
First Online: 4 July 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Waves 1 and 2 received ethical approval by the ethics committee of the University of Mannheim, Germany.