Authors’ contributions
MM
The study was designed by JC, JZ, AP, MM and RW. JC wrote the study protocol in close cooperation with JZ, AP, MM, UF and RW. MF performed the power calculation and gave advice for the statistical analyses in cooperation with MM. MB, JF, CG, MeKe, MaKi, RN, MS, PT, RV, MV, NV and LW all gave advice to improve the protocol. The manuscript was written by JC with input from JZ, AP, MM, RW, UF, MB, MF, JF, CG, MeKe, MaKi, CR, RN, MS, PT, RV, MV, NV and LW. All authors read and approved the final manuscript.