Impact of preoperative patient education on prevention of postoperative complications after major visceral surgery: study protocol for a randomized controlled trial (PEDUCAT trial) - Müller-Christmann, Christine; Diener, Markus K.; Bruckner, Thomas; Müller, Gisela; Stephan-Paulsen, Lisa M.; Keller, Monika; Büchler, Markus W.; Knebel, Phillip (Trials, 2013)