Participants and methods
RECRUITMENT
All procedures were performed at Zadar General Hospital, a single-center regional medical hospital, between July 2007 and December 2013. This study was retroactively registered in ISRCTN because at the time when it was approved by an institutional review board and recruitment started, registration was not required. Written informed consent was obtained from all patients before any study procedures were performed. This prospective, double-blinded, randomized controlled trial was approved by the Institutional Ethics Committee, General Hospital Zadar (01-1280/07). The study was conducted in accordance with the principles of the Declaration of Helsinki.