Funding for this research was provided by:
German Federal Ministry of Education and Research grant (01EO1002)
Received: 1 February 2018
Accepted: 4 April 2018
First Online: 2 May 2018
Ethics approval and consent to participate
: The present longitudinal, prospective cohort study was approved by the local ethics committee of the Friedrich-Schiller University, Jena, Germany (no. 3278-10/11). All participants have signed written informed consent and provided verbal consent before the telephone interview.
: All authors have provided consent for publication of the present manuscript.
: The authors declare that they have no competing interests.
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