Authors: Sebastian Haller; Christoph Eller; Julia Hermes; Martin Kaase; Matthias Steglich; Aleksandar Radonić; Piotr Wojtek Dabrowski; Andreas Nitsche; Yvonne Pfeifer; Guido Werner; Werner Wunderle; Edward Velasco; Muna Abu Sin; Tim Eckmanns; Ulrich Nübel Journal: BMJ Open Date: 2015-05-11 Impact factor: 2.692