Funding for this research was provided by:
Received: 24 November 2017
Accepted: 18 April 2018
First Online: 29 May 2018
Ethics approval and consent to participate
: Ethical approvals for the original studies, and further use of data (i.e. for the purposes of secondary data analysis), were obtained from the Ethics Committee of the State Chamber of Physicians (Landesaertzekammer; NCT00544557, 21 September 2007, and NCT00488475 15 September 2006). Consent to participate was obtained from all participants at the time of recruitment to each trial. At the time of recruitment, participants also provided consent for their data to be stored and used further without naming names (i.e. in secondary data analysis).
: NB has received research funding and lecture fees from Pfizer. MD, LA, and PS are employees of Pfizer and hold company stock or shares. AB is an employee of Quanticate and is a paid contractor to Pfizer. KLD declares that she has no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.