PeerJ Author 170 Points Contributions by role Author 135 Preprint Author 35 Contributions by subject area Epidemiology Gastroenterology and Hepatology Nursing Surgery and Surgical Specialties Karl Ove Hufthammer PeerJ Author Summary Clinical Trials Epidemiology Evidence Based Medicine Statistics Work details Biostatistician Haukeland University Hospital August 2012 Centre for Clinical Research Websites PubMed Search PeerJ Contributions Articles 1 Preprints 1 September 29, 2015 Employment status and sick-leave following obesity surgery: a five-year prospective cohort study John Roger Andersen, Ulrikke J.V. Hernæs, Karl Ove Hufthammer, Villy Våge https://doi.org/10.7717/peerj.1285 PubMed 26468438 March 24, 2015 - Version: 1 Employment status and sick-leave following obesity surgery: a five-year prospective cohort study John Roger Andersen, Ulrikke J.V. Hernæs, Karl Ove Hufthammer, Villy Våge https://doi.org/10.7287/peerj.preprints.923v1